Academic literature on the topic 'Oviposition preference. eng'

Hemipteran predator abundance varies significantly among crop species. Ovipositional preference by these predators for specific crops may help explain differences in predator abundance among crops. Ovipositional preferences of Nabis roseipennis Reuter between a preferred standard (soybean) and four crops (corn, tomato, tobacco and squash) were determined in paired-choice tests under greenhouse conditions. Significantly more eggs or egg groups were found in soybean than in corn and tomato. Squash was the only plant preferred for oviposition over soybean. Within-plant distribution of eggs varied among plant species and appeared to be independent of prey distribution. The specific site chosen for oviposition in each plant species apparently was determined by plant physical characteristics, possibly including rind toughness and, for tomato and tobacco, glandular trichome presence and age. Patterns of ovipositional preference were similar to previous observations of field abundance and may be partially responsible for those patterns.

Natural enemies play an important role in managing insect pests. Orius sauteri (Poppius) (Hemiptera: Anthocoridae), a predator of many soft-body insects, is an important biological control agent in Asia. Understanding this predator’s egg-laying preferences and a habitat needs is important for its success in pest control. We investigated the plant acceptability and ovipositional preference of O. sauteri for coriander (Coriadrum sativum L., Apiales: Apiaceae), marigold (Tagetes erecta L., Asterales: Asteraceae), sweet alyssum (Lobularia maritima L., Brassicales: Brassicaceae), and alfalfa (Medicago sativa L., Fabales: Fabaceae), and focused on the effects of plant physical and anatomical characteristics on the ovipositional preference of O. sauteri. The results showed that O. sauteri can lay eggs on uninfested plants in the vegetative stage and their eggs hatched normally. Orius sauteri females prefer plants with high stomatal density, a large stomatal area, and fewer trichomes as oviposition hosts, and the depth of egg placement was determined by leaf thickness. Our studies suggested that O. sauteri females can select oviposition hosts and specific oviposition sites by assessing the structural qualities of plant surface. Coriander and marigold are potentially suitable host plants for O.sauteri. The results aid the selection of cover crops to enhance natural enemies in the fields.

AbstractFactors that might contribute to variability in the densities of wheat midge eggs, Sitodiplosis mosellana (Géhin), on common and durum wheats, Triticum aestivum L. and Triticum durum Desf., were investigated to improve the quantification of oviposition preferences in relation to crop resistance. Egg densities on wheat spikes were highly variable, with a similar contagious distribution in the laboratory and field, although variance was highest in the laboratory. Females laid eggs in small groups, usually of one to six eggs; most infested spikes had more than one egg group. Females showed no preference for ovipositing on different parts of a spike, although spikelets on one side and at the base often received fewer eggs because these spikelets were covered by the flag leaf and inaccessible for longer than others. Oviposition rates varied from night to night, probably related to the weather. Females showed no preference for spikes at different growth stages, from the time spikes began to emerge until at least flowering. Spike size did not affect egg density, and spike height was a factor only for spikes deep within or protruding above the canopy. Sources of environmental variation such as effects of weather on oviposition rates in the field or spatial phenomena in cages were measurable but of secondary importance. In the field, comparisons among spikes which emerged on the same day could reduce variation in egg density. In the laboratory, variation in egg density could be reduced by using arrays of excised spikes arranged at the same height, leaving the central portion of the array empty. The primary cause of high variability in egg density among spikes was variation in egg-group size and the presence of multiple egg groups on a single spike, factors which cannot be experimentally controlled because they are the result of oviposition behaviour rather than environmental heterogeneity.

Abstract Drosophila suzukii (Matsumura) is a vinegar fly species that originates from Eastern Asia and has spread throughout Europe and the Americas since its initial detection in United States in 2008. Its relatively large, sclerotized, and serrated ovipositor enables the ability to penetrate ripening fruits, providing a protected environment for its egg and larval stages. Because the mechanism of oviposition site selection of D. suzukii is a matter of hypothesis, the aim of the present study was to elucidate behavioral and chemical aspects of short-range ovipositional site selection within the context of D. suzukii reproductive biology. The preference of D. suzukii to lay eggs on artificially pierced, previously infested, or intact fruits was tested. Video recordings and photographic evidence documented the release of an anal secretion over the fruit surface near the oviposition sites. Gas chromatographic analysis revealed the presence of 11 compounds detected only on the skin of egg-infested berries. Electroantennographic experiments with both sexes of D. suzukii highlighted the importance of six volatile compounds: methyl myristate, methyl palmitate, myristic acid, lauric acid, palmitic acid, and palmitoleic acid. Finally, a synthetic blend composed of the six compounds in a ratio similar to that found on the skin of egg-infested berries increased the oviposition rate of conspecific females. Data from our work suggest that the identified volatiles are cues for reproductive site selection. We discuss how these oviposition cues may affect the fitness of D. suzukii. The knowledge gained from this study may accelerate establishment of control strategies based on the interference and disruption of D. suzukii communication during the oviposition processes.

Background Oviposition site selection is an important factor in determining the success of insect populations. Orius spp. are widely used in the biological control of a wide range of soft-bodied insect pests such as thrips, aphids, and mites. Orius strigicollis (Heteroptera: Anthocoridae) is the dominant Orius species in southern China; however, what factor drives its selection of an oviposition site after mating currently remains unknown. Methods Here, kidney bean pods (KBPs) were chosen as the oviposition substrate, and choice and nonchoice experiments were conducted to determine the preferences concerning oviposition sites on the KBPs of O. strigicollis. The mechanism of oviposition behavior was revealed through observation and measurement of oviposition action, the egg hatching rate, and the oviposition time. Results We found that O. strigicollis preferred the seams of the pods for oviposition, especially the seams at the tips of the KBPs. Choice and nonchoice experiments showed that females did not lay eggs when the KBP tail parts were unavailable. The rates of egg hatching on different KBP parts were not significantly different, but the time required for females to lay eggs on the tip seam was significantly lower. Decreased oviposition time is achieved on the tip seam because the insect can exploit support points found there and gain leverage for insertion of the ovipositor. Discussion The preferences for oviposition sites of O. strigicollis are significantly influenced by the topography of the KBP surface. Revealing such behavior and mechanisms will provide an important scientific basis for the mass rearing of predatory bugs.

Tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), oviposition and longevity were examined when adult females were switched between cotton, Gossypium hirsutum (L.), and fleabane, Erigeron strigosus Muhlenberg ex Willdenow. Ovipositional rates and patterns were significantly affected by the sequence in which cotton and fleabane were offered. There was a rapid decrease in egg deposition when bugs were switched from fleabane to cotton. In contrast, a slow increase in oviposition occurred when bugs were switched from cotton to fleabane. Bugs laid more eggs on fleabane than on cotton when given a choice of host. There was no relationship between longevity and host sequence within years. Ovipositional preferences and host quality appeared to be responsible for differences in egg deposition.

Solanum viarum has been proposed as a potential dead-end trap crop for the management of Helicoverpa armigera because of its unsuitability for larval growth and survival despite being overwhelmingly preferred for oviposition. This study delved into the different S. viarum accessions for ovipositional preference and non-suitability for larval growth and survival of H. armigera. Besides, foliage trichomes, acylsugars, and phenolic content of S. viarum plants were assessed and compared with tomato. Since there is no significant variation in the ovipositional preference and larval performance of H. armigera, our result revealed that all those evaluated accessions of S. viarum have the potential to be used as a dead-end trap crop for the management of H. armigera. However, significant variation among the S. viarum accessions in terms of H. armigera oviposition was also evident in a no-choice experiment. Because of high-density glandular trichomes, acylsugars, and phenolic content, S. viarum significantly impaired H. armigera larval growth and survival compared to the tomato. Hence, our study elucidated that the S. viarum plant fits with the criteria for dead-end trap crop, and has the potential as a dead-end trap crop for the H. armigera, which needs to be tested under large, open-field conditions.

Abstract The present study was undertaken to verify ancient data in the literature on ovipositional preference of the cuttlefish Sepia officinalis for the terrestrial plant Pistacia lentiscus (mastic tree). -Adult specimens of Sepia were placed in basins together with aerial parts not only of P. lentiscus, but also of Artemisia arborescens, Centaurea alba var. deusta, Quercus ilex and Laurus nobilis. The egg masses deposited on the plants were quantified on a daily basis during the 16 day observation period. By far the largest amounts of eggs were found attached to the stems and petioles of P. lentiscus (51.8%), but Q. ilex and A. arborescens also scored high as ovipositional host plants (23.1 and 20.2% respectively). L. nobilis and C. alba var. deusta ranked very low (3.6 and 1.3% respectively). Considering the extremely divergent shape of the three preferred oviposition substrates, which excludes affinity for a uniform type of plant, the possibility of chemical attraction cannot be ruled out.

Soybean, Glycine max (L.) Merr., lines isogenic for dense (DE), normal (NL), and no (NO) pubescence developed from the cultivar ‘Tracy-M’ were used in free choice tests to determine their influence on corn earworm (CEW) Heliothis zea (Boddie) oviposition preference and distribution of eggs within plant canopy. Post oviposition performance of the isolines was determined. Of the total eggs deposited by CEW on excised leaves in a greenhouse oviposition arena, 64.5, 29.0, and 6.5% were on the DE, NL, and NO isolines, respectively. In a 614.2 m2 field cage study, 57.0, 30.9, and 12.1% of eggs deposited were on the DE, NL, and NO isolines, respectively. Within plant egg distribution was proportionally the same for the DE and NL isolines with 83.7, 13.5, and 3.8% of eggs deposited on leaves, stems, and fruiting structures, respectively. However, the within plant egg distribution on the NO isoline was 90.0, 0.9, and 9.3% deposited on leaves, stems, and fruiting structures, respectively. Isolines with the greater number of eggs senesced later, produced fewer pods and fewer seeds per pod than isolines with fewer eggs. However, isolines with the greater number of eggs produced larger seeds, which resulted in ca. the same total seed weight per plant as isolines with fewer eggs. There were no differences among isolines grown without oviposition for pod number, seed number, or seed weight. The strong ovipositional preference among the isolines, if properly developed and used, has potential for use in insect management programs.

AbstractAs agricultural practices intensify, species once common in agricultural landscapes are declining in abundance. One such species is the monarch butterfly (Danaus plexippus L.), whose eastern North American population has decreased approximately 80% during the past 20 yr. One hypothesis explaining the monarch’s decline is reduced breeding habitat via loss of common milkweed (Asclepias syriaca L.) from agricultural landscapes in the north central United States due to the adoption of herbicide-tolerant row crops. Current efforts to enhance monarch breeding habitat primarily involve restoring milkweed in perennial grasslands. However, prior surveys found fewer monarch eggs on common milkweed in grassland versus crop habitats, indicating potential preference for oviposition in row crop habitats, or alternatively, greater egg loss to predation in grasslands. We tested these alternative mechanisms by measuring oviposition and egg predation on potted A. syriaca host plants. Our study revealed that habitat context influences both monarch oviposition preference and egg predation rates and that these patterns vary by year. We found higher monarch egg predation rates during the first 24 h after exposure and that much of the predation occurs at night. Overall, we documented up to 90% egg mortality over 72 h in perennial grasslands, while predation rates in corn were lower (10–30% mortality) and more consistent between years. These findings demonstrate that weekly monarch egg surveys are too infrequent to distinguish oviposition habitat preferences from losses due to egg predation and suggest that monarch restoration efforts need to provide both attractive and safe habitats for monarch reproduction.

Resumo: Os intensos ataques de cigarrinha-das-raízes, Mahanarva fimbriolata, ocorridos em cana-de-açúcar, tem causado perdas econômicas expressivas. Devido a novas práticas culturais utilizadas no setor, ou seja, colheita de cana crua, aumentou significativamente a ocorrência e os danos provocados por esta praga na cultura. O trabalho foi conduzido em casa-de-vegetação e no Laboratório do Centro APTA - Cana-de-Açúcar do Instituto Agronômico, Ribeirão Preto-SP e teve por objetivos estudar a densidade adequada de adultos com o propósito de obter uma infestação suficiente para discriminação de variedades de cana- de-açúcar e a idade mais adequada da planta visando à realização de ensaios de resistência à cigarrinha-das-raízes; discriminar as variedades de cana-de-açúcar de importância econômica quanto à resistência de plantas a insetos de acordo com a excreção, atratividade, a não- preferência com e sem chance de escolha, a antibiose da cigarrinha-das-raízes e assim fornecer uma ferramenta a mais no manejo e controle dessa praga. Pela análise dos resultados conclui-se que M. fimbriolata prefere ovipositar em plantas com 25 e 35 dias de idade e, nas densidades de 2 a 5 casais por planta, depositaram número suficiente de ovos para diferenciar variedades de cana-de-açúcar após 48 horas da infestação. Na variedade SP80-1842, M. fimbriolata produziu uma maior quantidade de excreção em relação à variedade SP83-5073. As variedades RB83-5486, RB72-454 e SP80-1842 foram mais atrativas à cigarrinha-das- raízes que IACSP87-3396 e SP83-5073. Quanto à preferência para oviposição, SP83-5073, em teste com e sem chance de escolha, apresentou menor oviposição por M. fimbriolata. Ao analisar todos os parâmetros biológicos, constatou-se que a variedade SP80-1842 apresenta suscetibilidade a M. fimbriolata. As variedades SP83-5073 e IAC87-3396 determinaram... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The sugarcane spittlebug Mahanarva fimbriolata has inflicted intense attacks on sugarcane, resulting in expressive economic losses. Due to the new cultural practice of green harvest (mechanical), occurrence and damage by the spittlebug have increased significantly. This research was conducted in a greenhouse and at the laboratory of the "Centro APTA- Cana-de-Açúcar" in Ribeirão Preto, state of São Paulo, Brazil. The objectives were to study the adequate adult density to conduct experiments to ascertain which were the best age and varieties of sugarcane to be utilized in tests of resistence to the spittlebug; to discriminate economically important sugarcane varieties when checked for resistance to the spittlebug in trials of excretion, attraction, non-preference (choice and no-choice) and antibiosis. Results showed that the spittlebug preferred to oviposit in 25-35 days old plants, and at the density between 2-5 couples/plant it laid sufficient eggs to differentiate sugarcane varieties after 48 h of infestation. The spittlebug excreted more when fed on variety SP80-1842, when compared to variety SP83-5073. The varieties RB83-5486, RB72-454 and SP80-1842 were more attractive to the spittlebug than varieties IACSP87-3396 and SP83-5073. In trials with choice and no-choice, the spittlebug laid less eggs on variety SP83-5073. After analyzing all biological parameters, concluded that variety SP80-1842 showed susceptibility to the spittlebug. When fed on the varieties SP83-5073 and IAC87-3396 the spittlebug displayed the highest duration of incubation period, nymphal period and mortality, while the oviposition period and longevity of males and females shortened and fecundity dropped; antibiosis was the primary cause of resistance.
Orientador: Geraldo Papa
Coorientador: Leila Luci Dinardo-Miranda
Banca: Carlos Alberto Hector Flechtmann
Banca: Sérgio Luís de Carvalho
Banca: Adalton Raga
Banca: Mário Eidi Sato
Doutor

Egg-laying decisions can have significant fitness consequences. In female Drosophila melanogaster, egg-laying involves foraging-like behaviour. Natural allelic variation in foraging (for) underlies the rover/sitter foraging behaviour polymorphism found in D. melanogaster. for encodes a cGMP-dependent protein kinase (PKG) where rovers have higher for-PKG transcript levels and PKG activity than sitters. Interestingly, the orthologue of for in nematodes (egl-4) affects both egg-laying and foraging behaviours. When given a choice between low- and high-nutrient patches, rovers preferentially lay more eggs on the low-nutrient patches while sitters and a sitter mutant prefer high-nutrient patches. Using the neuronal driver elav-GAL4, rover-like preferences were rescued in sitter flies. Compared to sitters, rovers have higher fitness on a sub-optimal substrate which may explain the observed egg-laying preferences. By studying the link from genes to behaviour, this study provides insight to the evolutionary basis and maintenance of behaviour.