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Dissertations / Theses on the topic 'Lepidoptera ecology'
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1
Jones, Carys Wynn. "Habitat and rest site selection in polymorphic Lepidoptera." Thesis, University of Cambridge, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358332.
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Lees, David Conway. "Systematics and biogeography of Madagascan mycalesine butterflies (Lepidoptera: Satyrinae)." Thesis, University College London (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267759.
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Bédard, Caroline. "Chemical ecology of spruce seed moth, Cydia strobilella, L., Lepidoptera, tortricidae." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq37482.pdf.
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Roque-Albelo, Lazaro. "Diversity and ecology of the Lepidoptera in the Galapagos Islands, Ecuador." Thesis, Cardiff University, 2006. http://orca.cf.ac.uk/56156/.
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In this thesis the diversity and ecology of the Lepidoptera fauna of the Galapagos Islands, Ecuador are investigated. The study covers aspects of Lepidoptera diversity, their interactions with host plant and their seasonality. Diversity: The Galapagos Lepidoptera fauna is characterized by low diversification, a high level of endemism and prolonged geographic isolation. To date, 313 species of Lepidoptera are known to occur on the Archipelago and 64% of the native component of this fauna is endemic. Humans have introduced 62 species accidentally to the Islands. All Galapagos Lepidoptera are of American origin except the few introduced Old World species that are nearly cosmopolitan. Host plant relationships: Host plant data covering 155 species Galapagos species are reviewed, and new records of larvae of 113 species collected in the study area are presented. Most of the species are herbivores (272), with a few detritivores (13) and carnivores (3). Plants of the families Leguminosae and Asteraceae are the most common hosts for Galapagos species. Monophagy at the plant family level appears to be widespread in Galapagos Lepidoptera. Seasonality: The phenology of adult Sphingidae was studied at one locality in the arid zone of the southern slope of Santa Cruz Island, Galapagos for a period of 28 months (April 1999--August 2001). A total of 14 species, representing eight genera, was recorded during this study period. Sphingidae moths were more abundant in the wet season (December-May) with peaks occurring mid season. The number of specimens recorded decreased in the dry season (June-November) with the lowest numbers found in August. The seasonality and temporal stability (in terms of species diversity, population abundance and niche breadth) of this community is analysed.
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Engler, Helene Sari. "Chemical ecology of passion vine butterflies : sequestration of cyanogenic glycosides and patterns of host plant specialization by Heliconius butterflies /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
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Ringwood, Zoë K. "The ecology and conservation of Gortyna borelii lunata (Lepidoptera: Noctuidae) in Britain." Thesis, University of Essex, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397739.
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Fielding, Carol. "Aspects of the ecology of the Lepidoptera associated with heather Calluna vulgaris." Thesis, Durham University, 1992. http://etheses.dur.ac.uk/962/.
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Abbasipour, Habib. "Biology of grass-feeding Noctuidae (Lepidoptera) and their parasitoids in North East England." Thesis, University of Newcastle Upon Tyne, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318543.
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Shreeve, T. G. "The population biology of the speckled wood butterfly Pararge aegeria (L.) (Lepidoptera : Satyridae)." Thesis, Oxford Brookes University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.353595.
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Walton, Angela Jasmin. "Radiation biology of Eldana saccharina Walker (Lepidoptera: Pyralidae)." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6685.
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Ferguson, Kaye. "The biology, ecology and management of the Quandong moth, Paraepermenia santaliella (Lepidoptera: Epermeniidae)." Title page, contents and summary only, 2001. http://web4.library.adelaide.edu.au/theses/09PH/09phf3523.pdf.
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Includes bibliographical references (leaves 217-230). Details the biology and life history of the Quandong moth and investigates management strategies that would enable growers to manage the pest in an economically and environmentally sustainable program.
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Smee, Melanie Rose. "Population ecology and genetics of the marsh fritillary butterfly Euphydryas aurinia." Thesis, University of Exeter, 2011. http://hdl.handle.net/10036/3223.
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The past two decades have witnessed an unprecedented decline in Lepidopteran species, with more than a third of the UK’s butterflies now either considered threatened, or already lost from the country. The vulnerable marsh fritillary, Euphydryas aurinia, after a long term loss in the UK of 73% in abundance, has become an almost iconic species as the target of many well-funded conservation projects across the UK. Despite extensive ecological studies, populations of E. aurinia are shown in Chapter 2 to still be declining in south-west UK even after recommended management strategies have been implemented. This necessitates the need for prompt research beyond that of management requirements and butterfly habitat preferences. In Chapter 3, microsatellite markers (EST-SSRs) were developed for E. aurinia and using these markers in Chapter 4, it is shown that E. aurinia populations in southern UK and Catalonia, Spain, are severely genetically differentiated at all geographical scales, and genetically depauperate, causing huge concerns for the conservation of this enigmatic and ecologically important species. Dispersal is fundamental to metapopulation existence and survival. Phosphoglucose isomerase (PGI – an enzyme in the glycolysis pathway) is a well-endorsed candidate gene for dispersal, extensively studied in the Glanville fritillary (Melitaea cinxia) and Orange Sulphur (Colias eurytheme). In Chapter 5, an analysis across 27 sites in the UK discovered six non-synonymous SNPs (single nucleotide polymorphisms) within PGI. A single charge-changing SNP of interest showed no evidence of balancing selection, contrary to findings in M. cinxia, instead appearing to be neutral when analysed alongside microsatellite markers developed in Chapter 3. No link was found between genotype and flight, morphology or population trend. These findings challenge the emerging perspective that PGI could be used as an adaptive molecular marker for arthropods. Wolbachia are endosymbiotic bacteria capable of dramatically altering the reproductive system of their host. In Chapter 6, a PCR-based diagnostic in conjunction with MLST (multi-locus sequence typing) identified 100% prevalence of a single strain of Wolbachia across all sampled E. aurinia populations in the UK. Total prevalence suggests that Wolbachia probably has little phenotypic impact on its host, but the potential impacts of this endosymbiont on uninfected populations should be considered during any management plans for the conservation of E. aurinia. Current management plans will need to incorporate all areas of research, from basic ecological requirements to molecular adaptation and unseen manipulators of host biology, to be able to fully and effectively conserve declining fragmented species.
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Singer, Michael Stuart. "Ecological maintenance of food-mixing in the woolly bear caterpillar Grammia geneura (Strecker) (Lepidoptera: Arctiidae)." Diss., The University of Arizona, 2000. http://hdl.handle.net/10150/289114.
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Two major conceptual approaches for understanding the evolutionary ecology of insect-plant interactions, the plant-insect paradigm and the tri-trophic paradigm, have focused primarily upon dietary specialists and their host-plants. Here, I attempted to evaluate the utility of both paradigms for explaining the maintenance of food-mixing by the individually polyphagous caterpillars of Grammia geneura (Strecker) (Lepidoptera: Arctiidae). First, I conducted three experiments testing the hypothesis that individual G. geneura caterpillars perform better on mixed-plant diets than on single-plant diets due to improved physiological efficiency of food utilization. However, caterpillar performance was not always superior on mixed-plant diets. In the one case in which food-mixing improved performance, the host-plant species included in the mixture were individually of low suitability. Behavioral observations of individual caterpillars both in the above experiments, in nature, and in two further laboratory experiments with chemically-manipulated, synthetic diets supported the idea that such dietary benefits resulted from dilution of plant secondary metabolites, achieved behaviorally via the physiological mechanisms of neophilia and post-ingestive feedbacks on feeding. I also investigated the possibility that food-mixing was maintained by the unpredictable availability of high-quality host-plant species. A field survey of caterpillar feeding preference, frequency of parasitism, and host-plant availability suggested that this variation in food availability combined with the increased risk of parasitism incurred by individuals experiencing prolonged development (e.g. by searching excessively for a rare, preferred host-plant species) should favor polyphagy, and reinforce opportunistic food-mixing. However, because individual caterpillars showed a tendency to leave nutritionally superior host species for nutritionally inferior ones, I tested the idea that individuals ate some host-plant species for defense against parasitoids. Two experiments showed that diet modified the survival of parasitized caterpillars, and that at least one pair of host-plant species revealed a trade-off between their nutritive and defensive value to caterpillars. Taken together, the experiments in this study underscore the importance of the tri-trophic approach toward understanding the pattern and process of foraging in generalist as well as specialist herbivores.
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Allen, Geoffrey Rowland. "Behaviour and ecology of the primary parasitoids Cotesia urabae and Dolichogenidia eucalypti (Hymenoptera: Braconidae) and their host Uraba lugens (Lepidoptera: Noctuidae)." Title page, contents and preface only, 1989. http://web4.library.adelaide.edu.au/theses/09PH/09pha425.pdf.
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Han, Er-ning. "Laboratory studies on the regulation of migration in the oriental armyworm, Mythimna separata (Walker) (Lepidoptera: noctuidae)." Thesis, Bangor University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328851.
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Chidawanyika, Frank. "Thermal tolerance of Cydia pomonella (Lepidoptera : Tortricidae) under ecologically relevant conditions." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5375.
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Thesis (MSc (Agric) (Conservation Ecology and Entomology))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: Ambient temperature plays a key role in insect-physiology, -population dynamics and ultimately -geographic distribution. Here, I investigate the survival of codling moth, Cydia pomonella (Linnaues) (Lepidoptera: Tortricidae), which is a pest of economic importance in pome fruit production, to a wide range of temperature treatments. In this thesis, I first explore how temperature affects the survival and limits to activity of codling moth and secondly investigate if thermal acclimation can improve field performance of moths used in sterile insect technique control programmes under ecologically relevant conditions. First, I found that absolute temperature as well as the duration of temperature exposure significantly affects adult C. pomonella survival. Lethal temperatures, explored between -20 °C to -5 °C and 32 °C to 47 °C over a range of durations, showed that 50% of the adult C. pomonella population killed at -12 °C and at 44 °C after 2 hrs for each treatment. At high temperatures a pretreatment at 37 °C for 1 hr dramatically improved survival at 43 °C for 2 hrs from 20% to 90% (p<0.0001). Furthermore, high temperature pre-treatments (37 °C for 1 hr) significantly improved low temperature survival at -9 °C for 2 hrs. In sum, my results suggest pronounced plasticity of acute high temperature tolerance in adult C. pomonella, but limited acute low temperature responses. Secondly, low-temperature acclimated laboratory-reared moths were recaptured in significantly higher numbers (d.f. = 2, χ2 = 53.13 p<0.001), by sex pheromone traps, under cooler conditions in the wild relative to warm-acclimated or non-acclimated moths. However, these improvements in low temperature performance in cold-acclimated moths came at a cost to performance under warmer conditions in the wild. This novel study demonstrates the importance of thermal history on C. pomonella survival and clear costs and benefits of thermal acclimation on field and laboratory performance, and thus, the potential utility of thermal pre-treatments for improved efficacy in the sterile insect technique programme for C. pomonella control under cooler, springtime conditions. Finally, on a global scale, this study highlights that low and high temperatures could play a role in CM adult survival through direct mortality and thus, may influence, or have influenced in the pest, population dynamics.
AFRIKAANSE OPSOMMING: Temperatuur speel ‘n belangrike rol in die fisiologie, populasiedinamika en geografiese verspreiding van insekte. In hierdie tesis ondersoek ek die rol van ‘n wye reeks temperature op die oorlewing van kodlingmot Cydia pomonella (Linnaues) (Lepidoptera: Tortricidae), ‘n sagtevrug pes-spesie van ekonomiese belang. Ek ondersoek hoofsaaklik die effek van temperatuur op die fisiologie en fiksheid van kodlingmot, asook die mate waartoe termiese akklimasie (‘n mate van aanpassing) die veldgedrag van die steriele insek beheer-metode (SIT), d.m.v. kodlingot, in relevante omgewingstemperature kan verbeter. Ek het (i) gevind dat die temperatuur en duur van die temperatuur toediening ‘n betekenisvolle toename in volwasse C. pomonella oorlewing tot gevolg het. In die deel van die studie is temperature tussen -20 °C en -5 °C and tussen 32 °C en 47 °C ondersoek oor ‘n reeks van 0.5, 1, 2, 3 en 4 ure van duur. In kort lei -12 °C en 44 °C vir 2 uur onderskeidelik tot die uitsterf van 50% van die volwasse C. pomonella populasie. Indien die motte vooraf gehou is by 37 °C vir ongeveer 1 uur, is oorlewing by 43 °C vir 2 ure betekenisvol verbeter van 20% tot 90% (p<0.0001). Hoër temperatuur vooraf-blootstellings (akklimasie), by 37 °C vir 1 uur, het daartoe gelei dat lae temperatuur lae-temperatuur-oorlewings by -9 °C vir 2 ure betekenisvol verbeter het. Oor die algemeen het die resultate gedui dat hoër akute temperatuurstoleransie in C. pomonella bestaan, maar beperkte akute lae-temperatuur reaksies bestaan. Verder het lae-temperatuur akklimasie (laboratorium geteelde) motte ‘n betekenisvolle hoër getal hervangste deur geslagsferomone in koeler omgewings opgelewer (v.i. = 2, χ2 = 53.13, p<0.001) in vergelyking met warmer-temperatuur geakklimatiseerder motte. Hierdie verbeteringe in laetemperatuur reaksies vanaf lea-temperatuur akklimasie groepe is teen ‘n koste teen warmer reaksie-toestande in die natuur geïs. Hierdie eersdaagse studie demonstreer die belang van historiese temperatuur op die oorlewing van C. pomonella. Die kostes- en voordele van termiese akklimasie op veld- en laboratoriumpopulasie reaksies en die potensiële gebruik daarvan in die verbetering van steriele insek tegniek programme, onder koeler omstandighede, is uitgelig. Laastens, beklemtoon hierdie studie die belangrikheid van temperatuur as bepalende faktor van kodlingmot-oorlewing en die invloed daarvan op die vrugte-pes populasiedinamika.
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Justus, Kristine Ann. "Reproduction in diamondback moth, Plutella xylostella (L.) (Lepidoptera: plutellidae), morpology, behavior, and chemical ecology." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ34785.pdf.
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Mensah, Benjamin Andrew. "The physiological ecology of the phase polymorphism in the African armyworm moth, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae)." Thesis, Bangor University, 1995. https://research.bangor.ac.uk/portal/en/theses/the-physiological-ecology-of-the-phase-polymorphism-in-the-african-armyworm-moth-spodoptera-exempta-walker-lepidoptera-noctuidae(c12d1b26-0a5b-468e-8565-7e0bbe00b51a).html.
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The effects of larval phase polyphenism on adult reproductive biology, and larval nutritional and thermal ecology of the Af rican armyworm moth, Spodoptera exempta (Walker) were investigated. Differences between moths which were reared from solitaria and gregaria larvae were obtained in fecundity (weight-adjusted) and pre-oviposition period. Number of egg batches, oviposition period and longevity of female moths were inf luenced by adult di ' et and not by larval phase. Phase effects, on fecundity and pre-oviposition period were removed by rearing larvae as solitaria for three generations. Larval food consumption and utilization indices were affected by phase and instar; the direction of differences depended on whether solitaria larvae were first- or thirdgeneration. There were no differences in growth rates between phases. Weight-adjusted triglyceride contents of larvae were higher in the gregaria in two out of three trials. Solitaria larvae contained more body, -water. Rearing of larvae in different sizes of containers did not affect the triglyceride levels within phases, but affected water content in the solitaria. At constant ambient temperatures of 17.5,22.5 and 25"C, gregaria larvae developed faster than solitaria. At 300C, larval period was shorter for the solitaria than the gregaria. The rate of development did not differ between phases at 35"C. Gregaria larvae lost their black pigment at 350C and above. Anaesthetized black larvae attained higher rates of increase in temperature than larvae of lighter pigment when exposed to radiant energy. Loss of the black pigment at higher temperatures was accompanied by loss of ability of gregaria larvae to heat up faster under radiant energy. Studies on behaviour failed to demonstrate any preference of larvae in one phase for illuminated or shaded areas. The implications of these findings for the life history of S. exempta and the problems involved in research on phase polyphenism are discussed.
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Wayne, Heather. "Habitat Type and Ecotone Effects on Biodiversity of Hymenoptera, Diptera, and Lepidoptera." Kent State University Honors College / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ksuhonors1449861568.
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Hollingworth, T. S. "The influence of local wind effects upon the approach behaviour of some male lepidoptera to field pheromone sources." Thesis, Cranfield University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373998.
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Pinheiro, Julia de Lima. "Análise da conectividade funcional através da caracterização do movimento de Heliconius erato." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/11/11150/tde-06032018-175153/.
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A influência antrópica em habitats naturais pode causar perda e fragmentação florestal. Esse processo altera a quantidade de espécies, comprometendo a conservação biológica. Os efeitos da fragmentação dependem, dentre outras características, da conectividade entre os remanescentes. A conectividade funcional depende de como um organismo percebe e responde à estrutura da paisagem. Entender os fatores que determinam a qualidade da matriz para os organismos e entender o movimento animal são etapas essenciais para guiar iniciativas de conservação em paisagens fragmentadas. Como as borboletas são indicadas para o monitoramento ambiental, a partir da caracterização do movimento de indivíduos da espécie de borboletas Heliconius erato, foi possível inferir a respeito da sua capacidade de percepção e analisar a conectividade funcional da paisagem estudada. O estudo foi realizado na porção norte do município de Batatais, no interior do estado de São Paulo. Foi realizada a translocação de 78 indivíduos para a matriz a diferentes distâncias em relação a floresta e observado o seu caminho de retorno para a floresta. A taxa de retorno dos indivíduos translocados ao fragmento em função da distância foi avaliada pela análise de sobrevivência de Cox em conjunto com a razão entre os indivíduos que retornaram pela quantidade total por distância. A tortuosidade dos trajetos foi avaliada através da análise de Passos Aleatórios Correlacionados em conjunto com a razão entre a distância efetiva e a soma dos comprimentos para cada trajetória. Foi realizada uma análise de variância para avaliar se há diferenças de tortuosidade entre as distâncias. Para relacionar esse índice com a distância à floresta foram utilizados modelos lineares generalizados. Esses modelos foram comparados através do AICc. A orientação dos ângulos foi analisada através de estatística circular com teste de Rayleigh, teste-V e histogramas. Conforme aumenta a distância, diminui a quantidade de indivíduos que retornam à floresta. A taxa de retorno cai pela metade na distância de 150m. A partir da análise de Cox notou-se que a distância influencia a taxa de retorno dos indivíduos em conjunto com a tortuosidade e o local de soltura. A hora do dia e o local de soltura explicaram a variação na tortuosidade. A análise dos ângulos demonstrou que a partir de 150m os voos se tornam aleatórios. Dessa forma, para garantir a conservação do gênero Heliconius em paisagens agrícolas que incluem cultivos estruturalmente distintos dos fragmentos florestais é necessário manter uma distância de no máximo 100 metros entre os fragmentos.The anthropic influence on natural habitats may cause forest loss and fragmentation. This process changes species richness, compromising their conservation. The effects of forest fragmentation depend, among other factors, on the functional connectivity, namely on how an organism perceives and responds to the landscape structure. Understanding the factors that determine the quality of the matrix for the organisms and understanding animal movement are essential steps to guide conservation initiatives on fragmented landscapes. Therefore, from the movement characterization of the butterfly species Heliconius erato, which is indicated as a good surrogate for environmental monitoring, it was possible to infer about its perception capacity and to analyze landscape functional connectivity for this species. The study was conducted in the Northern region of Batatais, São Paulo. The translocation of 78 Heliconius erato individuals was conducted to non-forested matrix at different distances from forest patches and their paths back to the forest were actively recorded. The rate of return of the translocated individuals to their original forest patch as a function of the distance was evaluated with Cox survival analysis together with the ratio between the individuals which returned and the total amount per distance. Path tortuosity was measured through the Correlated Random Walk analysis together with the ratio between the effective distance and the sum of lengths for each path. An ANOVA was conducted to check for tortuosity differences between distances. To relate this index with the distance to the forest, generalized linear models were used. These models were compared through AICc. The angles orientation was analyzed through circular statistics with Rayleigh test, V-test and histograms. As distance increased the number of individuals returning to the forest decreased. The return rate dropped to 50% at 150m. Through Cox analysis it was noted that the distance together with tortuosity and release site influenced the return rate. The time of the day and the release site explained the tortuosity range. Angle analysis showed that as further than 150m the flights become random. Therefore, to ensure the conservation of the Heliconius genus in agricultural landscapes that include structurally distinct crops from forest fragments it is important to maintain a 100m mean inter-patch distance.
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Oye, Brian Koji. "Changes in the Vertical Stratification of Neotropical Nymphalidae at Forest Edges in Relation to Light and Temperature Conditions." Scholarly Commons, 2021. https://scholarlycommons.pacific.edu/uop_etds/3747.
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The composition of neotropical fruit-feeding nymphalid butterflies assemblages often varies by location and stratum within a forest. Recent work has shown that vertical stratification in particular may serve as barrier to gene flow, indicating the potential role vertical stratification may play in evolution. At forest edges, the distinction between assemblages has been described to decrease, with species considered to be canopy specialists descending to the forest understory. The similarity in light conditions between the canopy and understory strata at edges or disturbed habitat is hypothesized to be responsible for this phenomenon. We conducted a study using standardized sampling to document and quantify this edge effect, characterize edge and forest strata, and estimate the relative contributions of temperature and light conditions on nymphalid stratification. We found strong evidence of an edge effect in butterflies and confirmed strong differences in light and temperature showing that the edge understory differs little from forest canopy conditions. However, analyses here did not clearly implicate temperature or light in causing changes in neotropical nymphalid vertical stratification at forest edges.
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Haysom, Karen A. "Aspects of the ecology of the Lepidoptera associated with Calluna vulgaris on managed northern heath." Thesis, Durham University, 1994. http://etheses.dur.ac.uk/5597/.
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Aspects of the ecology of the Lepidoptera associated with Calluna vulgaris on managed northern heaths were studied between 1991-1993 at five study areas in Durham, Northumberland and southern Scotland. The study areas were northern heaths that were managed by rotational burning and each comprised a mosaic of even-aged Calluna stands. Lepidoptera were studied in the larval stage of development. A range of even-aged Calluna stands, with different ages and vegetation structures were selected as sample sites and the larval assemblages in the different stands were monitored by sweepnet sampling. A total of 29 species of macrolepidoptera and 3 species of microlepidoptera larvae were recorded. Species lists were similar at the five study areas, but the relative abundance of individual species varied between sites. The degree of similarity between communities was not related to the distance between study areas. The densities of many macrolepidoptera species were closely correlated with Calluna height. Intercorrelation between vegetation architecture variables meant that other factors e.g. green shoot density or flower density could also have been responsible. Lepidoptera diversity varied with Calluna height, due to changes in the dominance of common species and the presence of additional rare species at certain heights. However patterns in diversity were not consistent between study areas. The concentrations of total leaf nitrogen, total phenolics and water were significantly higher in current year's Calluna leaves than in the shoots formed in previous years. In same-aged leaves, there was no relationship between plant age and the concentrations of leaf nitrogen or phenolics. The water content of same-aged leaves was negatively correlated with stand age at some sites and at certain sampling times. Larvae offered different choices of ericaceous plants exhibited significant preferences for different plant species and also for the current year's Calluna leaves rather than previous years' growth. Mechanisms that could be responsible for the observed distribution patterns of larvae in different heights of Calluna are discussed. The maintenance of a mosaic of different-aged Calluna stands on northern heath represents the best conservation strategy for Lepidoptera by maintaining species diversity at a site.
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Rombe, Bandeira Romana. "The ecology of Papilio demodocus Esper (Lepidoptera: Papilionidae) on citrus tree plantations in southern Mozambique." Thesis, University of Aberdeen, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324147.
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Shuey, John Allen. "The ecology and evolution of wetland butterflies with emphasis on the genus Euphyes (Lepidoptera: Hesperiidae) /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487266362338099.
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Albertyn, Sonnica. "Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) population ecology in citrus orchards: the influence of orchard age." Thesis, Rhodes University, 2018. http://hdl.handle.net/10962/62615.
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Anecdotal reports in the South African citrus industry claim higher populations of false codling moth (FCM), Thaumatotibia (Cryptophlebia) leucotreta (Meyr) (Lepidoptera: Tortricidae), in orchards during the first three to five harvesting years of citrus planted in virgin soil, after which, FCM numbers seem to decrease and remain consistent. Various laboratory studies and field surveys were conducted to determine if, and why juvenile orchards (four to eight years old) experience higher FCM infestation than mature orchards (nine years and older). In laboratory trials, Washington Navel oranges and Nova Mandarins from juvenile trees were shown to be significantly more susceptible to FCM damage and significantly more attractive for oviposition in both choice and no-choice trials, than fruit from mature trees. Although fruit from juvenile Cambria Navel trees were significantly more attractive than mature orchards for oviposition, they were not more susceptible to FCM damage. In contrast, fruit from juvenile and mature Midnight Valencia orchards were equally attractive for oviposition, but fruit from juvenile trees were significantly more susceptible to FCM damage than fruit from mature trees. Artificial diets were augmented with powder from fruit from juvenile or mature Washington Navel orchards at 5%, 10%, 15% or 30%. Higher larval survival of 76%, 63%, 50% and 34%, respectively, was recorded on diets containing fruit powder from the juvenile trees than on diets containing fruit powder from the mature trees, at 69%, 57%, 44% and 27% larval survival, respectively. Bioassays were conducted to determine if differences in plant chemistry between fruit from juvenile and mature trees will have an impact on the susceptibility FCM to entomopathogenic nematodes (EPN), entomopathogenic fungi (EPF) and Cryptophlebia leucotreta granulovirus (CrleGV). No significant differences in the susceptibility of larvae reared on diets containing 15% fruit powder from juvenile and mature trees to EPN and EPF were recorded. Mortality of neonate larvae was significantly lower when placed on diets containing 15% fruit powder from mature trees (45% mortality) than diets containing 15% fruit powder from juvenile trees (61% mortality), after larvae ingested the lowest virus concentration tested, being 2 x104 OBs/ml. Data collected from field surveys showed significantly lower egg parasitism, virus infection of larvae and EPF occurrence in juvenile orchards than mature orchards. Egg parasitism was between 11% and 54% higher in mature orchards than juvenile orchards, with the exception of Mandarins during 2015, where egg parasitism was slightly higher in juvenile orchards, but not significantly so. A significantly higher proportion of larvae retrieved from mature orchards (7% of larvae) were infected with CrleGV than larvae retrieved from juvenile orchards (4% of larvae). A significantly higher occurrence of EPF was recorded in non-bearing and mature orchards, with 40% and 37% occurrence respectively, than in juvenile orchards, with 25% occurrence recorded. EPF occurrence in juvenile orchards increased significantly by 16% to 32% from the first to the third year of sampling. In contrast to results recorded in laboratory trials, similar or higher pest pressure in juvenile orchards than mature orchards did not always result in significantly higher levels of FCM damage under field conditions. FCM damage in juvenile orchards may have been lower than expected, as greater extremes of temperature and lower humidity were recorded in juvenile orchards, which would increase larval mortality. Results of this study showed that juvenile and mature orchards are significantly different and should be managed differently.
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Blanco-Metzler, Helga. "The biology and ecology of the Macadamia nutborer Ecdytolopha torticornis (Lepidoptera: Tortricidae) in Costa Rica." Thesis, University of Edinburgh, 1994. http://hdl.handle.net/1842/15091.
Full textAbstract:
This study presents a description of the life cycle and biology of the macadamia nutborer Ecdytolopha torticornis (Meyrick), and identifies factors which influence the abundance of the nutborer in a macadamia orchard in Atirro Farm, Turrialba, Costa Rica, during 1991-1993. Four larval instars were identified. The life cycle was completed in 36 days, and sex ratio of 1:1 was recorded. Fecundity was found to be 37 eggs per female. Macadamia clones differed in their susceptibility to nutborer attack: clones 344 and 246 were more heavily attacked than clones 508 and 660. The maximum level of nut damage was 37%. Nut damage decreased between years and sites. Four larval parasitoids (Apanteles I, Apanteles II, Pristomerus sp. and Ascogaster sp.) and one egg parasitoid (Trichogrammatidae) were reared. Parasitism presented a delayed-density dependence response to nutborer, abundance, as measured by nut damage. Apanteles I accounted for 40% of parasitoids reared, while Ascogaster accounted for 50%. Predation was found to be negatively affect the abundance of larvae in nuts on the ground, and the fire ant, Solenopsis invicta, was considered to be the most important predator. The nutborer preferred to oviposit upon nuts on branches within the first three meters from the ground, and the number of eggs laid was affected by weed management, more eggs were found when husk was applied as a mulch than in unweeded plots. Nitrogen content decreased with nut maturation. The nitrogen and tannin content of different clones were found to have no effect on the abundance of the nutborer. However, proanthocyanidin content and dry matter may affect larval performance. Evidence is given which supports the hypothesis that E. torticornis is a native species rather than an introduced pest. Four factors affect E. torticornis abundance, the quality of its food source, the quantity of the food source, predation and parasitism.
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Nascimento, Eduardo Silva. "Comportamento de chamamento e evidência de feromônio sexual em Atheloca subrufella (Hulst) (Lepidoptera: Phycitidae)." Pós-Graduação em Ecologia e Conservação, 2013. https://ri.ufs.br/handle/riufs/4421.
Full textAbstract:
The coconut moth, Atheloca subrufella (Hulst) (Lepidoptera: Phycitidae), is considered an important pest of coconut crop, especially in the Northeast of Brazil, which holds more than 70% of coconut production in the country. Its control is difficult because the caterpillars develop inside the flowers and fruits of the coconut palm, limiting the action of chemical agents. Thus, the use of pheromone for this insect management becomes quite promising. The objectives of this study were to describe the calling behavior of A. subrufella females and to verify the function of the pheromones involved in this process. The calling position, pattern and frequency of calling were evaluated. Female pheromone glands extracts were obtained and male and female volatiles were also collected by an aeration process, and were analyzed on a GC/MS to verify the presence of sex pheromones. The behavioral response of males was evaluated by bioassays using a Y-shaped-olfactometer containing a sample of female extracts. Analyzing the calling behavior, it was found that females of A. subrufella has only one calling position, and that this behavior has a peak between the second and fifth escotophases. Nor the duration of the calling or the number of calling bouts has changed over time, however, the beginning of the calling behavior was anticipated in older females, probably to avoid competition with younger females. Data showed that the best time to perform gland extractions and behavioral tests was between the third and seventh hour of the third or fourth escotophases. The chromatograms showed that it was not possible to demonstrate the presence of any female pheromonal compound, which was corroborated by the bioassays results, in which the male.s response did not indicate the presence of any pheromone. Thus, further studies are needed to elucidate the chemical structure of A. subrufella sex pheromone.A traça-do-coqueiro, Atheloca subrufella (Hulst) (Lepidoptera: Phycitidae), é considerada uma importante praga na cultura do coco, principalmente na região nordeste do Brasil, que concentra mais de 70% da produção de cocos do país. Seu controle é difícil, pois sua lagarta se desenvolve no interior das flores e frutos do coqueiro, limitando a ação de agentes químicos. Com isso, a utilização de feromônio para manejo desse inseto se torna bastante promissora. Nesse sentido, o objetivo desse trabalho foi verificar o comportamento de chamamento da traça-do-coqueiro, e determinar a função do feromônio sexual utilizado nesse processo. Foram avaliadas a posição de chamamento e o padrão e periodicidade da exibição desse comportamento. Os extratos foram obtidos de glândulas de feromônio de fêmeas virgens e a partir da aeração de machos e fêmeas. Os extratos foram analisados em cromatografia gasosa acoplada a espectrometria de massas (CG-EM). A resposta comportamental de machos foi avaliada através de bioensaios utilizando um olfatômetro em Y. Através da análise do comportamento de chamamento, verificou-se que as fêmeas de A. subrufella possuem apenas uma posição de chamamento, e que esse comportamento tem um pico entre a segunda e quinta escotofases. A duração do chamamento e o número de chamadas não modificaram com o passar do tempo, no entanto, o início do chamamento foi antecipado nas fêmeas mais velhas, provavelmente para evitar competição com fêmeas mais novas. Os dados demonstraram que o melhor horário para realizar as extrações e testes comportamentais foi entre a 3ª e 7ª horas da terceira ou quarta escotofases. A partir da análise dos cromatogramas obtidos não foi possível verificar a presença de compostos feromonais da fêmea, o que foi corroborado com os resultados dos bioensaios, em que a resposta do macho não indicou a presença de feromônios sexuais. Sendo assim, se fazem necessários novos estudos para evidenciar a presença e elucidar a estrutura química de um possível feromônio sexual de Atheloca subrufella.
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Giovenardi, Ricardo. "ESTUDO DA DIVERSIDADE DE BORBOLETAS (LEPIDOPTERA: RHOPALOCERA) EM DUAS LOCALIDADES NO MUNICÍPIO DE FREDERICO WESTPHALEN, RIO GRANDE DO SUL, BRASIL." Universidade Federal de Santa Maria, 2007. http://repositorio.ufsm.br/handle/1/5256.
Full textAbstract:
Contributing to the butterflies diversity knowledge from Estacional Decidual Forest of Rio Grande do Sul State, a systematic survey was carried out in two localities of the Municipal District of Frederico Westphalen: Villa Faguense Municipal Park and Schöenstatt Sanctuary, from March 2005 to April 2006. In 140 hours of sampling, were registered 3129 individuals distributed in 174 species. Of the sampled species, 56,32% belong to the Nymphalidae family
(12 subfamilies), 19,54% to Hesperiidae (2 subfamilies), 6,32% to Papilionidae (1 subfamily), 8,05% to Pieridae (3 subfamilies), 6,32% to Lycaenidae (2 subfamilies) and 3,45% to Riodinidae (1 subfamily). Ten species sampled were still no published for the State: Euptoieta hegesia (Cramer, 1779), Dynamine athemon (Linnaeus, 1758), Myscelia orsis (Drury, 1782), Pareuptychia summandosa (Gosse, 1880), Taygetis laches marginata (Staudinger, 1887), Yphthichoides castrensis (Schaus, 1902), Caligo eurilochus brasiliensis (Felder, 1826), Urbanus doryssus albicuspis (Herrich-Schaffer, 1869), Eurybia pergaea (Geyer, 1832), Lemonias zygia (Hübner, 1807). The Shannon-Wiener diversity index was higher in Villa Faguense Municipal Park, place less disturbed, and smaller in Schöenstatt Sanctuary. The Simpson and Berger-Parker dominance indexes had been more representative in Schöenstatt Sanctuary, with higher number of abundant species, and less representative in Villa Faguense
Municipal Park. Among the species captured 131 (75.29%) are accidental, 25 (14.37%) are accessory and 18 (10.34%) are constant species.Contribuindo para o levantamento sistemático e o conhecimento de borboletas da Floresta Estacional Decidual de Frederico Westphalen, foram realizadas saídas de campo mensais em duas localidades no Município, entre março de 2005 e abril de 2006. Em um total de 140 horas de amostragem, foram registrados 3129 indivíduos distribuídos em 174 espécies. Destas, 56,32% das espécies pertencem à família Nymphalidae (12 subfamílias), 19,54% Hesperiidae (2 subfamílias), 6,32% Papilionidae (1 subfamília), 8,05% Pieridae (3 subfamílias), 6,32% Lycaenidae (2 subfamílias) e 3,45% Riodinidae (1 subfamília). Foram registradas 10 espécies de borboletas ainda não publicadas para o Estado: Euptoieta hegesia (Cramer, 1779), Dynamine athemon (Linnaeus, 1758), Myscelia orsis (Drury, 1782), Pareuptychia summandosa (Gosse, 1880), Taygetis laches marginata (Staudinger, 1887), Yphthichoides castrensis (Schaus, 1902), Caligo eurilochus brasiliensis (Felder, 1826), Urbanus doryssus albicuspis (Herrich-Schaffer, 1869), Eurybia pergaea (Geyer, 1832), Lemonias zygia (Hübner, 1807). O ìndice de Diversidade de Shannon-Wiener foi maior no Parque Municipal da Vila Faguense, local menos perturbado, e menor no Santuário de Schöenstatt. Os índices de dominância de Simpson e Berger-Parker, por sua vez, foram mais representativos no Santuário de Schöenstatt, com maior número de espécies abundantes, e menos representativos no Parque Municipal da Vila Faguense. Foram registradas em Frederico Westphalen 131 (75,29%) espécies acidentais, 25 (14,37%) espécies acessórias e 18 (10,34%) espécies constantes.
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PONTES, Wendel José Teles. "Ecologia química e reprodução de Neoleucinodes elegantalis Guenée (Lepidoptera : Crambidae)." Universidade Federal Rural de Pernambuco, 2010. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6066.
Full textAbstract:
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
he reproduction in insects is affected by a wide array of factors that acts directly on the reproductive output, related with offspring quality and quantity: the interaction, by physical, chemical and visual cues, between insects and host plants; the larval growth rate affecting adult size and mating rate, as a mechanism of reproductive sucess. Thus, studies on insect reproduction are recommended to help estimate and to understand population dynamics, for both endangered species and to control crop pests. The tomato fruit borer Neoleucinodes elegantalis Guenée (Lepidoptera: Crambidae) is one of the most important pest species on Solanaceae in Brazil, and the aims of this works is to study this species regarding to: (i) the role of physical, chemical and visual cues on oviposition; (ii) the causes of sexual dimorphism and (iii) how male mating history affects his ability to obtain new matings. This work also propose an equation that can help to estimate the initial size of fragmented spermatophores found inside the reproductive tracts of females, based on measures of the fragments. The results showed: (i) that physical and chemical cues increase significantly the oviposition of N. elegantalis, as well showed that light intensityalso affect oviposition; (ii) that differences in dayly growth rate is the cause of the observedsexual dimorphism in this species, and (iii) that recently mated males are equally able to achieve new matings as virgin ones, within at least 24-h period.
A reprodução em insetos depende de diversos fatores que afetam diretamente o sucesso reprodutivo, em relação à qualidade e quantidade da progênie: a interação mediada por sinais químicos, físicos e visuais, entre o inseto e seu hospedeiro; taxa de crescimento larval relacionado com o tamanho final do adulto e a frequência de cópulas, como mecanismo de sucesso reprodutivo. Portanto, o estudo da reprodução de insetos é recomendado para se estimar e compreender a dinâmica de populações, tanto para a preservação de espécies em extinção, como para o controle de pragas agrícolas. A broca-pequena-do-tomateiro Neoleucinodes elegantalis Guenée (Lepidoptera: Crambidae) é uma das pragas mais importantes das solanáceas no Brasil, o que estimula o desenvolvimento de qualquer estudo voltado para a melhor compreensão de sua biologia e dinâmica populacional. Assim o objetivo deste trabalho é estudar (i) o efeito dos sinais físicos, químicos e visuais que afetam sua oviposição; (ii) as causas do seu dimorfismo sexual e (iii) o efeito da experiência de cópula de machos na sua capacidade de obter novosacasalamentos. Este trabalho ainda propõe uma equação que possa auxiliar em estimar o tamanho inicial de um espermatóforo já fragmentado, baseado nas medidas do fragmento encontrado no trato reprodutivo das fêmeas. Os resultados demonstram que: (i) os sinais físicos e químicos oferecidas estimulam significativamente a oviposição de N. elegantalis, bem como revela quepistas visuais afetam a oviposição; (ii) que a diferença na taxa diária de crescimento larval é responsável pelo dimorfismo sexual nesta espécie e (iii) que machos recém-copulados têm a mesma chance de conseguir uma nova cópula que um macho virgem, num período de 24 horas.
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Lomeli-Flores, Refugio. "Natural enemies and mortality factors of the coffee leafminer Leucoptera coffeella (Guerin-Meneville) (Lepidoptera: Lyonetiidae) in Chiapas, Mexico." Texas A&M University, 2007. http://hdl.handle.net/1969.1/85837.
Full textAbstract:
Through field surveys and laboratory experiments, this study assessed in part the
impacts of host plant, natural enemies, and weather variables on coffee leafminer
Leucoptera coffeella distribution and abundance at two elevations and two rainfall levels
in coffee farms in Chiapas, Mexico. In addition, a checklist of Neotropical coffee
leafminer parasitoids was assembled from field collections and literature review.
Coffee leafminer field incidence was positively correlated with leaf nitrogen content and
age, but in laboratory experiments coffee leafminers grew larger, developed faster, and
had higher survivorship on leaves with moderate (2.9±0.01%) versus low (2.5±0.04%)
or high (3.4±0.01%) nitrogen level, and on tough versus soft leaves. Ovipositional
preference was not generally for leaves that maximized offspring performance. Coffee
leafminer incidence was higher during the rainy versus dry season, and at low versus
high elevation. Shade cover reduced ambient temperatures within coffee farms, but did
not significantly affect coffee leafminer incidence. The coffee leafminer predator complex included 16 morphospecies, ~88% of
them ants (Formicidae), and contributed >58% of real mortality. Predation rates were
higher at high versus low elevation, and under high versus low rainfall. Predation was
the main source of coffee leafminer mortality throughout the year, and was highest
during the rainy season, when coffee leafminer incidence was highest.
Neotropical coffee leafminer parasitoids included 23 species of Eulophidae and
seven of Braconidae. In Chiapas, 22 larval parasitoid morphospecies were collected. Egg
and pupal parasitoids were not recovered. Parasitism accounted for <10% of real
mortality, and rates were 8-10-fold higher at low versus high elevation. Parasitism rates
were not significantly influenced by temperature or rainfall.
Coffee leafminer oviposited mostly during the night, and less under low versus
high temperatures. Average monthly temperature minima, which occur during the night,
were generally lower at high (~18°C) versus low (~20°C) elevation farms. The
incidence and abundance of coffee leafminer may differ between elevations due to
differences in temperature, because at high elevation lower temperatures likely reduced
coffee leafminer oviposition, and may have increased its mortality rate as a consequence
of longer development time and exposure to natural enemies.
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Souza, Camila Moreira de 1989. "Bioatividade de derivados de Annonaceae sobre Helicoverpa armigera (Hübner, 1808) (Lepidoptera: Noctuidae) /." Botucatu, 2016. http://hdl.handle.net/11449/138047.
Full textAbstract:
Orientador:, Edson Luiz Lopes BaldinCoorientador: Leandro do Prado Ribeiro
Banca: Carlos Frederico Wilcken
Banca: Antonio Eduardo Miller Crotti
Resumo: Helicoverpa armigera (Hübner, 1808) (Lepidoptera: Noctuidae) destaca-se pela grande capacidade de dispersão, hábito polífago e por ocasionar expressivos danos em culturas de interesse econômico em todo o mundo. Dentre os métodos de manejo de insetos-praga, o uso de derivados vegetais é considerado uma promissora alternativa ao controle químico, uma vez que estes produtos apresentam mais de um ingrediente ativo em sua composição, dificultando a seleção de insetos resistentes, além de serem provenientes de recursos renováveis. Dentre as famílias botânicas de ocorrência em regiões neotropicais, Annonaceae constitui uma das principais fontes de compostos naturais bioativos. Assim, visando disponibilizar alternativas mais sustentáveis e ao mesmo tempo eficientes para o manejo de Helicoverpa armigera (Hübner, 1808) (Lepidoptera: Noctuidae), avaliou-se a bioatividade de cinco derivados de anonáceas (Annona montana Macfad., A. mucosa Jacq., A. muricata L., A. reticulata L. e A. sylvatica A. St.-Hil.) e do produto comercial à base de acetogeninas de anonáceas (Anosom® 1 EC) sobre lagartas do inseto. Adicionalmente, o composto majoritário do extrato mais ativo foi identificado e também avaliado quanto à sua bioatividade sobre formas neonatas de H. armigera. Constatou-se que o extrato de A. mucosa (CL50: 411,55 mg kg-1 e CL90: 1.479 mg kg-1 ) assim como o Anosom® 1 EC (CL50: 312,08 mg kg-1 e CL90: 1.151 mg kg-1 ) apresentaram significativa atividade inseticida sobre H. armigera, com toxicidade aguda após sete dias de exposição a dieta artificial tratada. A partir do extrato etanólico de A. mucosa realizou-se fracionamento biomonitorado através de diferentes técnicas cromatográficas, permitindo o isolamento da acetogenina bisterahidrofurano roliniastatina-1. Este composto foi testado a uma concentração de 41,55 mg kg-1, ocasionando mortalidade total das larvas de H. armigera ...
Abstract: Helicoverpa armigera (Hübner, 1808) (Lepidoptera: Noctuidae) is a highly polyphagous species with high dispersion ability and adaptability to different crops of economic interest worldwide. Botanical insecticides emerge as a viable alternative to the use of synthetic insecticides for pest management because they have more of a potentially active ingredient in their composition, delaying the selection of resistant insect, moreover come from renewable resources. Among tropical plant families, the Annonaceae has shown great potential as a source of biopesticides. To determine an alternative tool for H. armigera control, this study evaluated the insecticidal activity of ethanolic seed extracts from five species of Annonaceae (Annona montana Macfad., A. mucosa Jacq., A. muricata L., A. reticulata L. e A. sylvatica A. St.-Hil.) and the acetogenin-based commercial bioinsecticide Anosom® 1 EC on larvae of H. armigera larvae. In addition, the major active compound of the ethanolic extract was isolated using various chromatographic techniques and assessed for its bioactivity on H. armigera neonates. In the initial screening assay we verified that the ethanolic seed extract from A. mucosa (LC50 = 411.55 mg kg-1 and LC90 = 1,479 mg kg-1 ) was the most promising one, showing similar effectiveness to Anosom® 1 EC (LC50 = 312.08 mg kg-1 and LC90 = 1,151 mg kg-1 ) against H. armigera at seven days after exposition to treated diet. The acetogenin bis-tetrahydrofuran rolliniastatin-1 was identified as the major compound in ethanolic extract from A. mucosa. This compound was assessed at 41.55 mg kg- 1, causing 100 % of larval mortality on H. armigera neonates for days after exposition to treated diet. After, in a greenhouse trial using tomato plants, the bioactivity of ethanolic extract of A. mucosa was compared to botanical insecticide Anosom® 1 EC (both at LC90) and a synthetic insecticide (Belt® 48 SC) ...
Mestre
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Mealor, Michael A. "Spatial heterogeneity in ecology." Thesis, University of Stirling, 2005. http://hdl.handle.net/1893/53.
Full textAbstract:
This project predominantly investigated the implications of spatial heterogeneity in the ecological processes of competition and infection. Empirical analysis of spatial heterogeneity was carried out using the lepidopteran species Plodia interpunctella. Using differently viscous food media, it was possible to alter the movement rate of larvae. Soft Foods allow the movement rate of larvae to be high, so that individuals can disperse through the environment and avoid physical encounters with conspecifics. Harder foods lower the movement rate of larvae, restricting the ability of individuals to disperse away from birth sites and avoid conspecifics encounters. Increasing food viscosity and lowering movement rate therefore has the effect of making uniform distributed larval populations more aggregated and patchy. Different spatial structures changed the nature of intraspecific competition, with patchy populations characterised by individuals experiencing lower growth rates and greater mortality because of the reduced food and space available within densely packed aggregations. At the population scale, the increased competition for food individuals experience in aggregations emerges as longer generational cycles and reduced population densities. Aggregating individuals also altered the outcome of interspecific competition between Plodia and Ephestia cautella. In food media that allowed high movement rates, Plodia had a greater survival rate than Ephestia because the larger movement rate of Plodia allowed it to more effectively avoid intraspecific competition. Also the faster growth rate, and so larger size, of Plodia allowed it to dominate interspecific encounters by either predating or interfering with the feeding of Ephestia. In food that restricts movement, the resulting aggregations cause Plodia to experience more intraspecific encounters relative to interspecific, reducing its competitive advantage and levelling the survival of the two species. Spatial structure also affected the dynamics of a Plodia-granulosis virus interaction and the evolution of virus infectivity. Larval aggregation forced transmission to become limited to within host patches, making the overall prevalence of the virus low. However potentially high rates of cannibalism and multiple infections within overcrowded host aggregations caused virus-induced mortality to be high, as indicated by the low host population density when virus is presented. Also aggregated host populations cause the evolution of lower virus infectivity, where less infective virus strains maintain more susceptible hosts within the aggregation and so possess a greater transmission rate. The pattern of variation in resistance of Plodia interpunctella towards its granulosis virus was found using two forms of graphical analysis. There was a bimodal pattern of variation, with most individuals exhibiting either low or high levels of resistance. This pattern was related to a resistance mechanism that is decreasingly costly to host fitness.
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Veldtman, Ruan. "The Ecology of southern African wild silk worms (Gonometa species, Lepidoptera: Lsiocampidae) consequences for their sustainable use /." Pretoria : [s.n.], 2004. http://upetd.up.ac.za/thesis/available/etd-02092006-083709.
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Hicks, Barry J. "The history, ecology and potential control of the pine beauty moth, Panolis flammea (Lepidoptera: Noctuidae) in Scotland." Thesis, University of Edinburgh, 2001. http://hdl.handle.net/1842/12079.
Full textAbstract:
The pine beauty moth, Panolis flammea, has been a serious pest of lodgepole pine in Scotland since 1976. It historically fed on native Scots pine but population levels of P. flammea on this host have not been high enough to cause tree mortality. This thesis reviews recent advances in the biology of the pest and documents control programmes targeted against the pest from 1976 to 2000. Practically uninterrupted population monitoring of the P. flammea occurred from 1977 to the present day in Scottish lodgepole pine plantations. While intervention with chemical spraying has occurred, there is an indication that the reductions observed in the unsprayed populations are the result of natural enemies. The compiled data suggested that populations of P. flammea have had a cyclic pattern over the monitoring period with outbreaks occurring at regular intervals of between 6 and 7 years. The amplitude of population cycles were large during the 1970s and 1980s, but have dampened in recent years. Natural enemies are believed to contribute to the cause of this trend. The population of P. flammea in Northern Scotland was severely affected by fungal disease during the summer of 1998. The fungi, Entomophaga aulicae, Batkoa major, Zoophthora sp., Nomuraea rileyi and Beauveria bassiana were recorded from P. flammea and infection of larvae by these fungi occurred in a density dependent fashion. The incidence of parasitism was different between the sites studied, however there was no difference in the parasitism between high and low density host populations. This is the first study to demonstrate that the diversity and impact of fungal pathogens affecting P. flammea is much greater now than in the past. Laboratory bioassays of the entomopathogenic fungus Beauveria bassiana against several life stages of the pine beauty moth P. flammea, showed that this fungus has the potential to be used as a biological control agent.
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Veldtman, Ruan. "The ecology of southern African wild silk moths (Gonometa species, Lepidoptera: Lasiocampidae): consequences for their sustainable use." Thesis, University of Pretoria, 2005. http://hdl.handle.net/2263/27468.
Full textAbstract:
The pupal cocoons of two southern African wild silkmoth species, Gonometa postica and G. rufobrunnea (Lepidoptera: Lasiocampidae), are composed of high quality silk and have potential as a commercially viable resource. However, limited ecological research has been done on these species, and their population dynamics is especially poorly known. A steady and predictable supply of cocoons is paramount to the economic sustainability of a wild silk industry. There is thus an urgent need for documenting and understanding the population dynamics of southern Africa’s Gonometa species. Here, the temporal and spatial variation of pupal (and thus cocoon) abundance, as well as associated natural enemies, are described for both Gonometa species for the first time. The larval parasitoid species emerging from parasitised pupae were quantitatively associated with species-specific emergence holes, making field-identification of these species possible. Eleven sites in total were sampled, over four generations, across the region where both species have historically reached high population densities. Apparent spatial synchrony in pupal abundance found between sites suggests that climate is responsible for observed population size fluctuations. As predicted from their life history traits, temporal variability was lower than expected for classically eruptive species. Gonometa species thus have an intermediate position on the population dynamics gradient. In turn, the responses of natural enemies were not predictable from Gonometa species defensive traits, but appear to be mediated by between-species cocoon strength differences. Using data on the number of G. postica pupae per tree and associated parasitism at several sites, the importance of the degree of spatial explicitness in the quantification of aggregation and the detection of density dependence was illustrated. The spatially explicit method gave different results and more information regarding the spatial pattern of pupal abundance and parasitism than non- and semi-explicit methods. Similarly, the detection of density dependence in parasitism rates was affected by the use of spatially explicit data, with the spatial explicit approach giving different and more biologically informative results than traditional, non-spatially explicit methods. This has marked implications for previous insect-host - parasitoid studies aimed at detecting density dependence. The variability in cocoon size, a surrogate for larval performance, adult fecundity and silk yield, revealed that gender, followed by species, contributed most to observed size differences, with no clear differences between generations or localities. Finally, the between-host plant and withinhost plant distribution ofG. postica and G. rufobrunnea pupae was quantified, chiefly investigating the deterministic nature of the choice of pupation site. The distribution of both species at these scales was found to be markedly non-random, with pupae generally preferring specific tree characteristics and micro-sites. These results now provide the basis for recommending an appropriate utilisation strategy for southern Africa’s wild silk moths. Based on the spatial and temporal variability in pupal abundance observed, a constant and predictable cocoon supply for natural harvesting is unlikely. Long-term, broad-scale documentation of Gonometa species population cycles may make it possible to predict cocoon availability in the future. Until such research is done, it is recommended that the current practise of only collecting cocoons from which moths have emerged be continued. Simultaneously, artificial rearing and seeding as alternative utilisation strategies should be experimentally explored based on the information gathered and patterns identified here.Thesis (DPhil (Entomology))--University of Pretoria, 2007.
Zoology and Entomology
unrestricted
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Sostak, Brendan E. "Effects of constant vs. fluctuating temperatures on performance and life history of the herbivorous pest Lymantria dispar (Lepidoptera: Eribidae)." VCU Scholars Compass, 2015. http://scholarscompass.vcu.edu/etd/4021.
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The role of temperature variation in organismal performance is understudied, but is critically important for understanding the response of biodiversity to climate change. To address this issue in herbivorous insects, I studied the direct and interactive effects of thermal regime (constant vs. fluctuating temperatures) and nutrition (dietary nitrogen) on gypsy moth (Lymantria dispar) performance under laboratory conditions. Predictions for differences between constant and fluctuating thermal conditions were derived from Jensen’s inequality, and artificial diets of differing nutritional quality were made by modifying nitrogen (casein) content. Larvae were reared in the laboratory under four temperature regimes (22°C constant, 22°C fluctuating (±6°C), 28°C constant, and 28°C fluctuating (±6°C)) and two diet treatments (high N, and low N). Gravimetric analyses were also conducted to calculate nutritional indices and assess the short-term effects of temperature and diet quality on fourth instar larvae growth efficiencies. Consistent with predictions from Jensen’s inequality, fluctuating thermal conditions significantly reduced larval performance in both sexes across ontogeny. Low quality diet also reduced performance, but interactions between diet and thermal regime were only found in early instars.
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Doyle, Annie Lynn. "Effects of Forest Fragmentation and Honeysuckle Invasion on Forest Lepidoptera in Southwest Ohio." Wright State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=wright1229873847.
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Santos, Jessie Pereira 1984. "Efeitos da estratificação vertical na comunidade de borboletas frugívoras na floresta atlântica estacional = Effect of vertical stratification on fruit feeding butterflies in atlantic forest, Brazil." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/315756.
Full textAbstract:
Orientador: André Victor Lucci FreitasDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Ecossistemas florestais apresentam variação na complexidade das estruturas vegetativas em um gradiente vertical, gerando diversos microclimas que influenciam a distribuição de grupos de animais neste ambiente. Em uma floresta de menor porte, como a Floresta Atlântica, as condições abióticas não tão distintas entre dossel e subosque não configurariam diferenças marcantes entre as comunidades neste gradiente. E ainda, devido à menor distância entre os dois estratos, esperaríamos encontrar uma composição de espécies similar forrageando tanto no dossel quanto no subosque. Já em um contexto de estrutura filogenética de comunidades, se este gradiente representa um filtro ambiental, pode estar moldando atributos das espécies e o tipo de habitat em que ocorrem. Espécies que possuem atributos semelhantes sejam estes morfológicos ou propriamente o nicho tende a co-ocorrer em um mesmo ambiente, caracterizando um agrupamento filogenético. Dessa forma esperaríamos encontrar uma distribuição não aleatória dos clados ao longo do gradiente vertical. Utilizando armadilhas com iscas atrativas dispostas alternadamente no dossel e subosque ao longo de seis transecções, investigamos o efeito da estratificação vertical na estruturação da comunidade de borboletas frugívoras em uma formação de Floresta Estacional Semidecidual na Floresta Atlântica. Em um ano de amostragem, obtivemos 2047 indivíduos, divididos em 69 espécies de borboletas de quatro subfamílias. A abundância, riqueza e diversidade foram maiores no dossel, mas a composição da comunidade foi distinta entre os estratos. As quatro subfamílias de borboletas frugívoras ocuparam preferencialmente o dossel, incluindo a tribo Satyrini comumente relacionada ao subosque em estudo anteriores. Estes resultados sugerem que a estrutura da vegetação na Floresta Atlântica possui uma configuração que fornece recursos específicos para as borboletas frugívoras nos estratos mais altos, ou que o porte menor da floresta permite a estas borboletas contornarem os fragmentos de mata, da borda até o alto. Embora não saibamos exatamente quais os fatores que moldam os padrões de estratificação vertical neste bioma, corroboramos a alta diversidade contida no dossel e o efeito deste gradiente na estruturação de comunidades em uma floresta tropical de menor porte. Encontramos um forte sinal filogenético demonstrando que o tamanho de asa é conservado nos clados. Houve variação na composição filogenética, com as linhagens de Charaxinae concentradas no dossel enquanto as demais subfamílias estiveram mais associadas ao subosque. A diversidade filogenética foi superior no subosque e decresce em direção ao dossel. Essa variação está relacionada à maior diversidade de linhagens no subosque e a dominância de Charaxinae no dossel. O tamanho de asa diferiu entre os estratos, com borboletas maiores concentradas no subosque, entretanto essa diferença não se manifestou através da filogenia. Nossos resultados demonstraram que a presença de sinal filogenético do atributo tamanho não foi necessariamente preditora da conservação de nicho neste caso. A presença de um filtro ambiental, possivelmente a pressão de predação, ou a capacidade de voar entre espaços reduzidos parece estar selecionando tamanhos de asa neste gradiente. Medidas e atributos que reflitam o histórico evolutivo das borboletas frugívoras podem auxiliar na compreensão dos padrões de distribuição desta guilda em florestas tropicais
Abstract: Forest ecosystems include a wide variation in the complexity of vegetation structures in a vertical gradient, resulting in different microclimates that influence the distribution of animal groups in these environments. In forests with lower canopy, such as the Atlantic Forest, abiotic factors may not be sufficiently different to cause a clear pattern of vertical stratification, causing similar community compositions. Additionally, if the vertical gradient plays a role of habitat filter in relation to phylogenetic structure of community, species traits are expected to be adapted to this gradient, as well as their habitats. Species with more similar morphological traits or niche will tend to co-occur in the same habitat, characterizing a phylogenetic clustering. Thus, it would be expected to find a non-random distribution of clades along the vertical gradient. This study aims to investigate the effects of vertical stratification in a community of fruit-feeding butterflies in a seasonal semi-deciduous formation of the Atlantic Forest, using bait traps alternately disposed at understory and canopy levels. During a one-year sampling period, we recorded 2047 individuals of 69 species of butterflies, classified into four subfamilies. Abundance, species richness and diversity were higher in the canopy, and species composition differed along the vertical strata. All four subfamilies of fruitfeeding butterflies preferentially occupied the canopy, including the tribe Satyrini, commonly associated to understory in previous publications. Our results suggest that vertical structure of vegetation in the Atlantic Forest provides specific food sources to fruit feeding butterflies in the higher strata, or the smaller height of the forest allows those butterflies to fly above the fragments, from the edge to the top. Although we do not know for sure which factors are shaping the patterns of vertical stratification in this biome, we corroborated the high diversity in canopy and the effect of the vertical gradient on the structure of a fruit-feeding butterfly community in a low-canopy forest. We found a strong phylogenetic signal for wing size, confirming it as conserved within clades. Besides that, the two strata showed differences in the phylogenetic arrangement, with lineages of Charaxinae more associated to the canopy, unlike the remaining subfamilies, related to understory. The phylogenetic diversity was higher in the understory and decreased towards the canopy. This variation can be explained by the higher diversity of lineages in the understory and the dominance of Charaxinae in the canopy. Wing size differed between strata, with larger butterflies found in the lower levels, however this difference was not related to phylogeny, but due to an effect of habitat filter. The presence of a phylogenetic signal for one trait does not necessarily predict conservatism niche in this case. It is possible that pressure of predation or the ability to fly in reduced spaces are acting as habitat filters, and selecting wing sizes along the vertical gradient. Traits and other measurements linked to historical evolution of fruit-feeding butterflies may be useful to better understand the distribution patterns of this guild in tropical forests
Mestrado
Ecologia
Mestre em Ecologia
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Sétamou, Mamoudou. "Ecology and pest status of Mussidia nigrivenella Ragonot (Lepidoptera: Pyralidae), a cob borer of maize in West Africa." [S.l. : s.n.], 1999. http://deposit.ddb.de/cgi-bin/dokserv?idn=958529973.
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Muli, Benjamin Kimwele. "The biology and ecology of Mussidia spp. (Lepidoptera : Pyralidae) and associated natural enemies in Kenya / Benjamin Kimwele Muli." Thesis, North-West University, 2009. http://hdl.handle.net/10394/4114.
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Mussidia nigrivenella Ragonot (Lepidoptera: Pyralidae), an important pest of maize, cotton and Phaseolus bean in West Africa, has never been described as a crop pest from East and southern Africa (ESA). It was hypothesized that in ESA it was either kept under control by natural enemies or that there exist several populations of M. nigrivenella with different host plant ranges. Another possibility is the mis-identification of the Mussidia species in ESA. Studies were conducted in Kenya between 2005 and 2007 to assess the species diversity and host plant range of Mussidia spp. and spatial distribution studies were done on selected host plants. Later, based on the results of host plant range, surveys were conducted between 2006 and 2007 in mid-altitude coastal Kenya to establish a catalogue of parasitoids associated with Mussidia spp. The suitability of stem borers found in Kenya for development of Trichogrammatoidea sp. nr lutea Girault (Hymenoptera: Trichogrammatoidea) and the factors affecting the bionomics of Mussidia sp. in the laboratory were examined. Eight plant species were found to host two Mussidia spp. and six putative morphospecies, which occur sympatrically in the coastal region. The two Mussidia spp. were Mussidia fiorii Ceconni and de Joannis and M. nr nigrivenella. Only one Mussidia sp., M.Jiorii, was found attacking one host plant species in the mid-altitude regions. In general, the host plant range was much narrower than in West Africa. Mussidia nr nigrivenella and Mussidia "madagascariensis" larval distribution was aggregated on Canavalia cathartica Thouars. (Fabaceae) and Strychnos madagascariensis Poir. (Loganiaceae), respectively, while the distribution of M. fiorii adults on Kigelia africana (Lam.) Benth. (Bignoniaceae) was regular. Eight parasitoid species were recovered from Mussidia spp. eggs and larvae and include the trichogrammatid egg parasitoid Trichogrammatoidea sp. nr lutea Girault, a braconid egg-larval parasitoid, Phanerotoma sp., the bethylid Goniozus sp. and the braconid Apanteles sp. Moreover, the ichneumonid larval parasitoid Syzeuctus sp. was obtained from M. fiorii, while the tachinid Leskia sp. was obtained from M, "madagascariensis". Trichogrammatoidea sp. nr lutea, the only parasitoid species which was successfully reared in the laboratory, successfully attacked and developed on eggs of six lepidopteran hosts indicating its potential to exploit other alternate lepidopteran pests of maize in West Africa. Like the parasitoid species, only one Mussidia sp., M.fiorii, was successfully reared in the laboratory and it developed on maize seed-, Canavalia enseiformes L. DC (Fabaceae) seed- and maize leaf-based diets while it could not develop on Mucuna pruriens L. DC (Fabaceae) seed- and C. cathartica seed-based diets. The lower developmental thresholds for M. fiorii eggs, larvae, pupae and egg to adult were found to be 12.8±0.25°C, 14.4±0.27°C, 11.0±0.03°C and 13.5i0.2rc, respectively, while the thermal constants were 82.0±1.61, 384.6±9.43, 144.9±6.84 and 588.2±10.81 degree days, respectively. Adults started emerging during the last hour of photophase and peak emergence was observed in the 2nd hour of scotophase. Mating activity largely took place between the 4th and 5th hour of scotophase. It can be concluded that there exist several Mussidia spp. in Africa that vary in their host plant range. Overall, mortality caused by parasitoids was negligible hence they were unlikely to explain the population dynamics of the Mussidia spp. in Kenya. The fact that Trichogrammatoidea sp. nr lutea successfully attacks and develops in six lepidopteran hosts, including two Mussidia spp. indicates its potential for use as a biological agent against M. nigrivenella in West Africa. Mussidia fiorii was able to develop on diets based on maize and C. enseiformes. The knowledge on dietary and thermal requirements would optimize mass production of the host and natural enemies. The present study revealed again a serious bottleneck for biocontrol worldwide, namely the
proper identification of the pest and natural enemy species as a result of an ever dwindling number of taxonomists. We therefore suggest that molecular (DNA) techniques should be used in addition to detailed morphological examination. In view of the fact that natural control will not be effective in case of accidental introduction of the West African M. nigrivenella into Kenya, we suggest stringent precautions during movement of grains especially maize between the West Africa region and Kenya.Thesis (Ph.D. (Environmental Sciences and Management))--North-West University, Potchefstroom Campus, 2009.
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Kristiansen, Evan B. "Phylogeography of a highly variable butterfliy species in Western North America: Speyeria callippe (Lepidoptera: Nymphalidae)." Scholarly Commons, 2014. https://scholarlycommons.pacific.edu/uop_etds/183.
Full textAbstract:
Traditionally, methods for phylogenetic and phylogeographic inference have relied heavily on morphological data. Molecular data can provide an independent assessment of patterns and are particularly desirable when morphology may be under natural selection. Herein we present a phylogeographic analysis of the highly polytypic butterfly, Speyeria callippe. Samples were drawn from 71 populations across western North America. Phylogeographic trends are inferred from analysis of the gene Cytochrome oxidase subunit I ( CoI ). Patterns of mtDNA diversity imply historical panmixia and Mid-to-late Pliocene divergence from other Speyeria approximately xx mya. Diversification within the species appears to have occurred primarily during the Pleistocene. The data partially support a hypothesis of multiple waves of diversification following the climatic fluctuations of glacial and interglacial periods. Speyeria callippe was found to be paraphyletic containing both Speyeria egleis and Speyeria edwardsii. The genetic variation observed within S. callippe was highly structured reflecting local geography. However, this did not extend to larger scales as subspecies and major color pattern groups were not recovered as monophyletic, consistent with the large amount of overlapping morphological variation. Overall, intraspecies differentiation in morphology and mtDNA observed here indicate S. callippe is a young species complex with potentially adaptive color pattern variation that is in a relatively early stage of sorting into geographically separate entities.
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David, Paul Joseph. "Bionomics of Platynota flavedana Clemens and P. idaeusalis (Walker)(Lepidoptera: Tortricidae) in Virginia apple orchards." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/54282.
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The effects of pheromone trap placement on male moth catches of both species were studied. For P. flavedana, traps hung at 2.1 and 3.0 meters captured the greatest number of moths. Trap heights of 1.2, 2.1, and 3.0 meters caught the greatest number of P. idaeusalis moths. The outside-the-canopy trap position captured more P. flavedana moths, while the within-canopy trap location caught the greatest number of P. idaeusalis moths. Traps placed in the west portion of the tree captured the greatest number of P. flavedana moths. P. idaeusalis moth catches were not influenced by compass quadrants. Trap design and pheromone dispenser and rate influenced trap catches of P. flavedana.
Development of P. flavedana and P. idaeusalis on a meridic diet was observed at constant temperatures in the laboratory. Lower developmental threshold values for egg, larval, and pupal stages of P. flavedana were: 10.6, 8.6, 9.0°C, respectively. Lower developmental threshold values of 9.7, 7.0, and 8.5°C were estimated for P. idaeusalis egg, larval, and pupal stages, respectively. An average of 101.5 °D10.6’, 379.6 °D8.6’, and 126.0 °D9.0’ were required for development of egg, larval, and pupal stages of P. flavedana, respectively. P. idaeusalis required 104.7 °D9.7’, 442.7 °D7.0’, and 132.2 °D8.5’ to complete development in the egg, larval, and pupal stages, respectively. Differences in rate of development were observed between food sources for both species.
Within-tree spatial distribution of egg masses and fruit damage resulting from larval feeding for both species was investigated. P. flavedana egg masses were mostly found in the southern portion of the tree below 1.8 meters. Egg masses of P. idaeusalis were observed in greatest numbers in the southern and eastern quadrants of the tree below 2.8 meters. Fruit damage caused by larvae of both species was greatest in the lower portion of the tree. Wind dispersal of first-instar larvae between trees is believed to have influenced fruit damage distribution.
The seasonal activity of P. flavedana and P. idaeusalis was monitored. Degree-day accumulations for first moth catch, first and peak egg deposition, and first and peak egg hatch of both generations are presented.Ph. D.
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Silva, Danilo Germano Muniz da. "Composição e sazonalidade de borboletas frugívoras no cerrado, com ênfase na relação fenológica entre Eunica bechina (Nymphalidae: Biblidinae) e sua planta hospedeira Caryocar brasiliense (Caryocaraceae)." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/316184.
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Orientadores: Paulo Sérgio Moreira Carvalho de Oliveira, André Victor Lucci FreitasDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Em muitos ambientes tropicais, estações chuvosas se alternam com períodos de seca. A estação seca é um período de menor disponibilidade e qualidade nutricional de folhas, sendo, portanto, um período desfavorável para insetos herbívoros e gerando as oscilações sazonais em suas populações. O cerrado é um bioma neotropical sazonal, que inclui formações de savana (cerrado sensu stricto), e onde o clima se caracteriza por uma estação quente e chuvosa de outubro a abril e uma fria e seca de maio a setembro. A produção de folhas novas se concentra geralmente na estação chuvosa, tornando este um período favorável para muitos insetos herbívoros tais como as borboletas. Em seu estágio larval, as borboletas são herbívoros vorazes cujas populações comumente oscilam de acordo com a disponibilidade de folhas adequadas ao desenvolvimento dos imaturos. Borboletas podem ser divididas funcionalmente em duas guildas: as que se alimentam em sua forma adulta do néctar de flores, e aquelas que se alimentam dos líquidos oriundos de frutos em decomposição, seiva de árvores, carcaças de animais e excrementos. As espécies do segundo grupo são conhecidas como borboletas frugívoras. A guilda de borboletas frugívoras tem sido amplamente utilizada em estudos de ecologia de comunidades devido à facilidade de captura usando armadilhas com iscas de fruta fermentada, e a relativa facilidade de identificação. Entretanto, poucas vezes esta comunidade foi estudada em ambientes abertos, e raramente em trabalhos envolvendo sazonalidade. Nesta dissertação exploramos a sazonalidade das borboletas frugívoras do cerrado sensu stricto em dois capítulos. No primeiro abordamos a composição da comunidade, suas alterações ao longo do ano bem como suas oscilações de abundância. A maior abundância de borboletas ocorreu no meio da estação chuvosa, enquanto o pico de riqueza ocorreu ao final desta estação. Satyrini foi o grupo mais abundante na estação chuvosa (principalmente Yphthimoides manasses), enquanto na estação seca foi Biblidinae (principalmente Hamadryas februa). No segundo capítulo analisamos em detalhe a relação fenológica entre a borboleta Eunica bechina e sua planta hospedeira, o pequizeiro Caryocar brasiliense. Esta planta possui nectários extraflorais atrativos para formigas, que patrulham a planta e atacam as larvas de E. bechina. Observamos a maior ocorrência de larvas no início da estação seca, quando ocorreu a maior produção de folhas. Ovos e larvas estavam presentes em quase todos os meses de amostra, exceto no final da estação chuvosa. Propomos que este seja um período de inatividade reprodutiva na espécie, devido à baixa disponibilidade de folhas jovens
Abstract: In many tropical environments, rainy and dry seasons alternate. The dryer season has decreased leaf availability and the nutritional quality of leaves is also low - thus it is an unfavorable period for herbivorous insects and generates seasonal oscillations in their populations. The cerrado is a neotropical seasonal biome characterized by a hot/rainy and a cold/dry season. Leaf production is generally concentrated in the rainy season, which is the favorable period for herbivorous insects such as butterflies. In its larval stage, butterflies are voracious and specialized herbivores, and their populations commonly oscillate according to the availability of adequate leaves for immature feeding. Butterflies can be categorized in two functional guilds according to the food resources utilized by the adults: one group feeds on flower nectar, whereas another group of species feed on the liquids from rotting fruits, carcasses and excrements, and also plant sap. The latter group is known as fruit-feeding butterflies. Fruit-feeding butterfly guild has been widely used in studies of community ecology because they are easily captured using traps with fermented fruit, and also easily identified. Surprisingly, however, fruit-feeding butterflies have rarely been studied in seasonal, open environments. In this dissertation we investigated the seasonality of fruit-feeding butterflies in the cerrado sensu stricto. In the first chapter we decribe the composition of the community, changes through the year, and oscillations in its abundance. The greatest abundance occurred in the mid rainy season, while richness peaked at the late rainy season. Satyrini was the most abundant group in the rainy period (mainly Yphthimoides manasses), whereas Biblidinae (mainly Hamadryas februa) was more common in the dry season. In the second chapter we analyze in detail the phenological relationship between the butterfly Eunica bechina and its hostplant Caryocar brasiliense. The larvae feed only on the young leaves of C.brasiliense that bear extrafloral nectaries, which attract ants that patrol the plant and attack E. bechina larvae. We observed the larger occurrence of larvae in the early rainy season, when most young leaves are produced. Eggs and larvae where present at almost all sampling months, except in the late rainy season. We suggest that this is a period of reproductive inactivity in the species, due to the low availability of young leaves
Mestrado
Ecologia
Mestre em Ecologia
45
Lehnert, Matthew Steven. "Ecology and population biology of the Jamaican Giant Swallowtail, Papilio (Pterourus) homerus Fabricius (Lepidoptera : Papilionidae), in the Cockpit Country, Jamaica." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0012104.
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Baker, Amanda J. "Comparing the effects of the exotic cactus-feeding moth, Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae) and a native cactus-feeding moth, Melitara prodenialis (Walker) (Lepidoptera: Pyralidae) on two species of Florida Opuntia." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001801.
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Lemoine, Nathan. "The Effects of Climate Warming on Plant-Herbivore Interactions." FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/2244.
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Rising temperatures associated with climate change will alter the fundamental physiological processes of most ectothermic species. Drastic changes in catabolic and anabolic reaction rates exert strong effects on growth, reproduction, and consumption rates that cascade up through all levels of the biological hierarchy. This dissertation determined how climate warming might alter the important relationship between plants and insect herbivores, as mediated through changes in herbivore physiology. Consumption and fitness increased with temperature for almost all consumers. However, all consumers also exhibited a critical temperature, beyond which consumption declined rapidly through metabolism continued to increase. This mismatch in metabolic demands and energy intake reduced consumer fitness at high temperatures. Furthermore, increased metabolic nitrogen demand can induce nitrogen limitation in insect herbivores at high temperatures. These basic physiological changes can modify the way herbivores interact with plants in a number of ways. For example, the Japanese beetle, Popillia japonica, altered its feeding behavior on numerous host plant species, depending on host plant quality. Unfortunately, the effects of temperature on plant-herbivore interactions will be difficult to predict, as there was no predictable relationship between consumption and temperature across numerous plant-herbivore pairs. Finally, rising temperatures disrupt insect herbivore control of plant fitness, thereby altering one of the most important components of plant-herbivore interactions. Thus, climate change will fundamentally change the nature of plant-herbivore interactions in the future.
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Mudavanhu, Pride. "Performance of sterilized Eldana saccharina Walker (Lepidoptera: Pyralidae) adults in mating and cage trials : further steps towards its control using the Sterile Insect Technique." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71727.
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Thesis (PhD(Agric))--Stellenbosch University, 2012.The sugarcane borer, Eldana saccharina Walker (Lepidoptera: Pyralidae) is the most limiting factor in the South African sugar industry with losses to this insect pest estimated to be at least ZAR60 million per annum. Because of its cryptic nature as well as the fact that E. saccharina is both indigenous to Africa and occurs on several host plants, attempts to control or eradicate it using several available methods have not been very successful. However, the sterile insect technique (SIT) is one of the newer control methods that can be incorporated into an area-wide integrated pest management (AW-IPM) programme to achieve better control or eradication. The implementation of the SIT program needs to go through a series of well-researched phases in order to be successful. In the first of this multi-phase project, it was determined that E. saccharina is susceptible to ionizing radiation, and is thus a suitable candidate for the SIT development against it and that a sub-sterilizing dose of 200 Gy is sufficient to induce F1(inherited) sterility in male and complete sterility in female moths respectively. The results presented here are discussed in the context of further development of the SIT as an addition to the arsenal of tactics in an AW-IPM programme against E. saccharina. Based on these initial findings, the study examined the lek and mating behavior of male moths subjected to three radiation doses (150, 200, 250 Gy) against normal non-irradiated/fertile moths. Both mass-rearing and irradiation of E. saccharina led to a quantitative departure of male mating behavior away from that exhibited by their wild counterparts. However, treated males are still able to form leks and mate with wild females. Male E. saccharina irradiated at all three doses tested were found to be as active and competitive as wild males, but in some of the traits measured, performance diminished significantly with an increase in the radiation dosage. In general, the performance of moths treated at 200 Gy did not differ significantly from that of moths treated at 150 Gy and therefore the former dose is ideal for SIT development since it results in a lower residual F1 fertility than the latter. The level of mating competitiveness and compatibility was assessed under both laboratory and semi-field conditions in pairwise comparisons consisting of laboratory reared vs. wild (L-W), 200 Gy irradiated vs. wild (S-W) and laboratory reared vs. irradiated moths (L-S). Based on the results from the more robust field cage assays, the mating indices generated indicated that the mass-reared E. saccharina strain produced in South Africa has not yet evolved sexual behaviours suggestive of incipient pre-mating isolation barriers with local wild strains. Wild moths did not discriminate against either the partially sterile or laboratory reared moths and most importantly, the irradiated males mated significantly more than their wild counterparts regardless of the type of female. The irradiated insects could therefore achieve the purpose for which they are intended upon release into the field. Third, the critical thermal limits (CTLs) to activity at high and low temperatures (i.e. critical thermal maxima “CTmax” and minima “CTmin”) of different E. saccharina strains/treatments were investigated under standard experimental conditions. The effect of laboratory rearing and increasing radiation dosage on thermal tolerance of the adult stage of E. saccharina was explored. There were highly significant differences between the laboratory-reared and wild strain and also between non-irradiated and irradiated strains in both CTmax and CTmin. Laboratory reared E. saccharina moths were more heat tolerant compared to wild moths for both genders while in the case of CTmin, the reverse was true. Irradiation had a negative effect on both CTmax and CTmin. Moths treated at the lowest radiation dose were more cold and heat tolerant than those treated at higher dosages thereby reinforcing the importance of lower dosages rather than those that induce full sterility against E. saccharina. In general, gender effects on the CTLs were non-significant. Pilot sterile male releases in shade house trials to measure the impact of sustained releases of partially sterile adult males at an over-flooding moth ratio of 10T: 1U (treated to untreated),were conducted to measure their efficacy to stop E. saccharina incursions and suppress populations prior to testing in pilot studies under true season-long and area wide conditions. Results from the current study demonstrated that releasing partially irradiated (200 Gy) adult male moths at the afore mentioned release rate significantly reduced sugarcane stalk damage as well as lowered the number of fertile progeny from F1to succeeding generations in a stable E. saccharina population initiated in a cage house. There were more damaged internodes per stalk in the control than in the sugarcane receiving regular releases of partially sterile male moths. Overall, there were significantly more undamaged stalks in the treated sugarcane than the untreated control. Furthermore, there were significantly more larvae per stalk retrieved from the control compared to the treated sugarcane suggesting that the sustained release of steriles was efficacious in reducing emergence of fertile larvae in the succeeding generations. The results of this study indicate that there is considerable scope for the SIT against E. saccharina.
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Ramos, Renato Rogner. "Padrões alares e efeitos da fragmentação de habitat na estrutura genetica de Heliconius erato phyllis (Fabricius, 1775) (Lepidoptera, Nymphalidae, Heliconiini)." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/316267.
Full textAbstract:
Orientadores: Vera Nisaka Solferini, Ronaldo Bastos FranciniTese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Espécies com distribuições continentais podem ocupar várias zonas climáticas e diferentes vegetações, e forças seletivas locais podem gerar diferenças entre populações. A borboleta Heliconius erato phyllis possui esse tipo de distribuição e o teste G revelou diferenças significativas nos padrões de coloração das asas anteriores entre machos de diferentes regiões, mas não entre fêmeas. Melanismo, seleção sexual, atividade hormonal e predação podem estar envolvidos. O número de raios vermelhos nas asas posteriores apresentou correlação positiva com o comprimento das asas anteriores (CAA), mas exceções sugerem que tamanho e temperatura atuem como ativadores de hormônios que elevam a concentração de pigmentos para a formação dos raios. ANOVA demonstrou médias do CAA diferentes entre as populações, e o teste de Tukey apontou os maiores indivíduos em 3 sítios costeiros. Uma análise de componentes principais apontou altas temperaturas, pluviosidade e estabilidade climática como fatores ligados ao grande CAA. Esses fatores possivelmente contribuem com o crescimento de hospedeiras e com o desempenho larval. Técnicas moleculares usando marcador microssatélite foram aplicadas nas populações, em três escalas geográficas e uma temporal. Os resultados mostram grande variabilidade genética e populações sem isolamento por distância em escala continental. A reprodução é panmítica e os indivíduos possuem alta capacidade de dispersão mesmo entre fragmentos urbanos. Na escala temporal ocorreram diferenças estruturais moderadas, provavelmente devido a gargalos. Estudos em populações fragmentadas e de ampla distribuição ajudam a entender os efeitos do isolamento sobre a estrutura genética dessas populações e propor planos de manejo e conservação.
Abstract: Species with continental distribution can take several climatic zones and different vegetations, and local selective forces can generate differences among populations. The Heliconius erato phyllis butterfly has this kind of distribution, and the ?G? test showed meaningful differences on forewing color-patterns among males from different regions, but not among females. Melanism, sexual selection, hormonal activity and predation may be involved. The number of red raylets on hindwing show positive correlation with forewing's length (CAA), but exceptions suggest that size and temperature as triggers hormones that raise the concentration of pigments in the formation of raylets. The ANOVA showed different average on CAA among populations and the Tukey's test showed greatest individuals on 3 coastline sites. A principal component analysis indicated high temperatures, rainfall and climatic stability as major factors responsible for the large CAA. These factors possibly contribute with the growth of host-plant and the larval performance. Molecular techniques using microsatellite marker were applied on populations under three geographic scales and one temporal scale. The results show has a great genetic variability and populations without isolation by distance on continental scale. The reproduction is panmitic and the individuals have high dispersal ability even among urban fragments. On the temporal scale occurred moderate structural differences; probably due to bottlenecks. Studies on widespread and fragmented populations, help to understand the effects of isolation over the genetic structure of populations, and propose management and conservation plans.
Doutorado
Ecologia
Doutor em Ecologia
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Embid, Felipe Miguel Libran. "Efeitos da estrutura da paisagem sobre o controle biológico do bicho-mineiro-do-cafeeiro (Leucoptera coffeella, Lepidoptera: Lyonetiidae) provido por aves e morcegos." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/41/41134/tde-28092015-112604/.
Full textAbstract:
O controle biológico de pragas agrícolas é um dos serviços ecossistêmicos mais valorizados, dada sua importância para a produção agrícola. Embora vários estudos tenham demonstrado que a abundância e riqueza de predadores aumentam com a quantidade de floresta nativa, os mecanismos subjacentes que modulam a relação entre a cobertura florestal e provisão de controle biológico em diferentes escalas espaciais são ainda pouco conhecidos. Neste trabalho, utilizamos experimentos de exclusão de vertebrados voadores em oito paisagens cafeeiras na Mata Atlântica, num gradiente de cobertura florestal, e quantificamos as consequências para a perda foliar e para a frutificação. A perda foliar mostrou uma relação negativa com a cobertura florestal em paisagens com 2 km de raio, indicando que a herbivoria é melhor controlada em paisagens com alta cobertura florestal, especialmente na presença de aves e morcegos. No entanto, no nível local, 300 m ao redor das plantas de café, a perda foliar e a frutificação responderam diferentemente à cobertura florestal. Em unidades com baixa cobertura florestal local, a exclusão de aves e morcegos aumentou a perda foliar e diminuiu a frutificação em uma média de 13%. Por outro lado, em unidades com alta cobertura florestal local, a exclusão de aves e morcegos não teve efeitos significativos nem na perda foliar, nem na frutificação. Concluímos que os efeitos da exclusão de aves e morcegos na perda foliar e frutificação são modulados por diferentes processos que ocorrem no nível local e da paisagem. Sugerimos que quando a cobertura florestal local é alta (geralmente perto de fragmentos florestais), as aves e os morcegos não se alimentam apenas de herbívoros, mas também de mesopredadores. No entanto, quando a cobertura florestal local é baixa (e.g. longe de fragmentos florestais), os mesopredadores não ocorrem e aves e morcegos passam a prover serviço de controle biológico de pragas, alimentando-se principalmente de herbívoros. Destacamos a importância de empregar uma análise multiescalar em sistemas onde espécies com diferentes capacidades de dispersão proveem um serviço ecossistêmico.Biological control of agricultural pests is one of the most important ecosystem services given its key role for agricultural production. Although several studies have shown that the abundance and richness of predators increase with the amount of native forest in the landscape, the underlying mechanisms relating forest cover at different spatial scales with the provision of biological control are still poorly understood. We experimentally excluded flying vertebrates (birds and bats) in eight coffee landscapes in the Brazilian Atlantic Forest, encompassing a gradient of forest cover and quantified the consequences for coffee leaf loss and fruit set. Leaf loss showed a negative relation with forest cover at landscape level, in landscapes with 2 km radius, indicating that herbivory is better controlled in landscapes with high forest cover, especially in the presence of birds and bats. However, at local level, 300 m around coffee plants, leaf loss and fruit set responded to forest cover differently. In units with low local forest cover exclusion of birds and bats increased leaf loss and reduced fruit set by 13% in mean. However, in units with high local forest cover, exclusion of birds and bats had no significant effect neither on leaf loss nor in fruit set. We concluded that the effects of birds and bats exclusion on leaf loss and fruit set are modulated by different processes occurring at landscape and local levels. We hypothesized that when local forest cover is high (usually near remnant forest fragments) birds and bats are not only controlling herbivores but may also be reducing mesopredators, while when local forest cover is low (e.g. far from forest fragments), mesopredators do not occur and birds and bats start providing biological pest control by feeding mainly on herbivores. We highlight the importance of employing a multiscale analysis in systems where species with different dispersal abilities are providing an ecosystem service.