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Dissertations / Theses on the topic 'Semiochemical'

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Published: 4 June 2021
Last updated: 9 February 2022

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1

Pathak, Shrey. "Piezoelectric microsensors for semiochemical communication." Thesis, University of Warwick, 2012. http://wrap.warwick.ac.uk/57210/.

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Chemical communication plays vital role in the mediating the behaviour of an organism living in the “odour space”. The mechanisms by which odours are generated and detected by the organism has evolved over thousands of years and thus the potential advantages of translating this system into a fully functional communication system has opened new avenues in the area of multi-disciplinary research. This formed the basis of the Biosynthetic Infochemical Communications project – iCHEM whose central aim was to develop a new class of communication technology based on the biosynthesis pathways of the moth, S. littoralis. This novel infochemical communication system would consist of a “chemoemitter” unit which would generate a precise mix of infochemicals which after travelling through the odour space would be detected by a complementary tuned detector – the “chemoreceiver” unit comprising of a ligand specific detection element and an associated biophysical model functioning similar to the antennal lobe neuron of the moth. This combined novel system will have the capability of communicating by the help of chemicals only, in the vapour or liquid phase. For the work presented in this thesis, the novel concept of infochemical communication has been examined in the vapour and liquid phase by employing piezoelectric microsensors. This has been achieved and demonstrated throughout the thesis by employing chemo-specific acoustic wave microsensors. For vapour phase assessment, quartz crystal microbalance, were coated with different organic polymer coatings and incorporated in a prototype infochemical communication system detecting encoded volatiles. For liquid phase assessment, shear horizontal surface acoustic wave (SH-SAW) microsensors were specifically designed and immobilised within Sf9 insect cells. This GPCR based whole cell biosensing system was then employed to detect ligand specific activations thus acting as a precursor to the development of a fully functionalised OR based signalling system, thus contributing to the growing field of communication and labelling technology.
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Becker, Stuart David. "Semiochemical Detection of Infection Status in House Mice." Thesis, University of Liverpool, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.485899.

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Female preference expressed through mate choice for attractive males represents a fundamental mechanism for the selection and propagation of heritable advantageous traits in animal populations. The presence of pathogenic infection in males can alter female mate choice, commonly rendering affected males less attractive than uninfected conspecifics, although there are several exceptions. It has been suggested that in wild populations, variation between males in their ability to cope with infection may be reflected in differences in signalling. Signals may include secondary sexual characteristics, behaviour, or other changes associated with clinical pathology. Recognition of these signals could provide a reliable estimate of heritable resistance to locally relevant pathogens, as highly resistant males may invest more heavily in signals of attractiveness or suppress indicators of pathology, and so experience greater reproductive success. Heritable resistance in the context of local pathogens is likely to increase offspring survival, so improving the reproductive success of both the male and female parent. Interpretation of female preference behaviour from an ecological perspective demands that experimental design takes into account the evolutionary history of the host-pathogen combination under study. Natural host-pathogen combinations are likely to be mutually adapted through co-evolution, resulting in optimisation of avoidance and transmission strategies respectively. Thus observations gained through experimental use of naturally occurring pathogens in wild study populations are more likely to elicit ecologically relevant responses than non-natural pathogens. A serological survey during this project found variable prevalence of several viral pathogens in wild and wild-derived captive populations of house mice (Mus domesticus). This survey also found that most viruses showed low or no transmission in captivity, with the exception oflymphocytic choriomeningitis virus (LCMV). As this pathogen is an important zoonosis, the captive population was screened to eliminate LCMV and thus remove any associated risk to personnel. Transmission of LCMV occurred vertically (to the foetuses in utero) in most cases, and several animals that were persistently infected with virus had no detectable antibody to this pathogen. This has important implications for standard laboratory screening for LCMV, where the use of serological methods alone could fail to detect persistent infections. The effects of immune stimulation and viral infection on male competitive behaviour and female preference for males and their scents were investigated. Previous studies had demonstrated infectionassociated changes to urinary scent signalling. Thus urine of control, vaccinated and infected animals was subjected to biochemical analysis. Immune stimulation was achieved by vaccinating animals with the novel antigen keyhole limpet haemocyanin. During infection studies, animals were inoculated with mouse adenovirus, a natural pathogen of wild mice that had been identified during the serology survey. Immune stimulation caused small a reduction in male scent marking behaviour, but did not alter female preference or urine biochemistry. Infection caused no change to male urine marking behaviour, but reduced urinary protein concentration. This did not alter female preference. Pregnancy block or the 'Bruce' effect may represent a mechanism females could use to avoid the deletenous effects of infection on offspring. Laboratory studies have demonstrated that female mice will termmate gestation if exposed to an unfamiliar male within a limited time after mating. As these studies ofte.n use inbred laboratory strains, males are classed as 'unfamiliar' if they arw of a different inbred stram to the stud male. However, scent changes associated with infection may provide a different source of unfamlhanty. The 'Bruce' effect is traditionally assumed to have evolved as it offers potential advantages.to both males and females. However, we show that female mice are able to control whether pregnancy is blocked or maintained by altering their own exposure to male scent at times critical for the activation of this physiological mechanism. Thus females may control'the 'Bruce' effect without reference to male advantage, and this behaviour may have evolved solely to improve female reproductIve success.
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Viviers, Marlize Zaretha. "Investigation into the semiochemical communication involved in neonatal offspring recognition in sheep." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/3980.

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Thesis (PhD (Chemistry and Polymer Science))--University of Stellenbosch, 2010.
Video 1: Twin-bearing Döhne Merino ewe butting only one of her lambs in typical rejection behavior. Rejection of one twin is not a common phenomenon. (Video by Dr Marlize Viviers)
Video 2: Twin-bearing ewe # 22 accepting alien lamb # 179. The alien lamb wears a jacket her other lamb has been wearing for the preceding 24 hours. The excessive sniffing at the jacket, bleating and looking around show that the ewe is not totally satisfied with the situation. (Video by Dr Marlize Viviers)
Video 3: Ewe # 22 rejecting alien lamb # 179 after removal of the jacket it has worn in the previous video. (Video by Dr Marlize Viviers)
ENGLISH ABSTRACT: Sheep husbandry substantially contributes to South Africa’s economy. Lamb mortality is regarded as a major constraint to sustainable sheep production, and an important factor in lamb survival is the strong ewe–lamb bonding. This is a well-known phenomenon in all sheep races and strong evidence exists that the selective ewe–lamb bond formation has a pheromonal basis, in that the ewe can distinguish her lamb by its unique, familiar smell. Sheep farmers and scientists have examined various methods of making alien lambs acceptable to foster ewes. The survival rate of offspring could be substantially increased if a reliable method could be devised to prevent ewes from rejecting their own lambs or if ewes could be induced to accept alien lambs. A better understanding of the semiochemicals involved in this communication between ewe and offspring could facilitate the development of a method by which ewes can be coaxed into adopting foster lambs. This would positively contribute to efficient sheep production in South Africa. The objective of this study was to characterise the volatile constituents present in the wool and the amniotic fluid collected from the Döhne Merino lambs to achieve a better understanding of the ewe–lamb semiochemical communication. The volatile organic constituents associated with the wool and amniotic fluid were characterised and a total of 133 volatile organic compounds were identified. Several compound classes are represented in these samples and the majority of these compounds have previously been identified in the excretions and secretions of numerous mammalian species. A number of different aspects of ewe–lamb kin recognition were investigated. First, the odour profiles of twin lambs were compared to those of other twins. The results of these analyses revealed that the wool volatiles of twin lambs are qualitatively as well as quantitatively practically identical, but different from those of other lambs in the flock. Second, the change in the odour profiles of lambs was studied over a seven-day period. It was found that the odour profiles of lambs are not fixed, and for as long as a ewe makes use of olfactory recognition as the main mode of identification of her lamb she has to continue learning the odour of her lamb. Third, the amniotic fluid was investigated as a possible source of maternal labels, i.e. as chemical codes consisting of mixtures of compounds in specific quantitative ratios that are imprinted on lambs by their mothers at birth. It was found that the amniotic fluids of first- and second-born lambs are qualitatively and quantitatively different. It is possible that the duration of the lambing birth process could contribute to this change in amniotic fluid composition. Fourth, the role of residual proteins in the dissemination of the semiochemicals involved in ewe– lamb communication was investigated and six proteins were identified as amniotic fluid and wool-associated proteins. Bioassays carried out during the lambing season of 2009 confirmed the role of the odour of the lamb in ewe-lamb recognition, but bioassays carried out with synthetic pheromone formulations gave inconclusive results.
AFRIKAANSE OPSOMMING: Skaapboerdery lewer aansienlike bydrae tot die ekonomie van Suid Afrika, maar lamsterftes is een van die kwellende probleme waarmee kleinveeboere te kampe het. Die eksklusiewe band wat binne die eerste paar uur na 'n lam se geboorte tussen die ooi en haar lam ontwikkel, is die hooffaktor waarvan lammers se oorlewing afhang. Hierdie sterk binding tussen lam en ooi is 'n bekende verskynsel in alle skaap-rasse en dit is bekend dat 'n feromoon wat deur die lam vrygestel word, dit vir die ooi moontlik maak om haar lam aan sy unieke reuk uit te ken. Lamsterftes sou aansienlik verminder kon word as hierdie feromoon geïdentifiseer en gebruik kan word om ooie te verhoed om hulle eie lammers te verwerp en om die aanvaarding van vreemde lammers deur ooie moontlik te maak. Die doel van hierdie studie was die chemiese karakterisering van die vlugtige organiese verbindings aanwesig in die amniotiese vloeistof en wol van Döhne Merino lammers ten einde 'n beter begrip van die semiochemiese kommunikasie tussen ooie en lammers te verkry. In die amniotiese vloeistof is 70 vlugtige organiese verbindings geïdentifiseer. Dieselfde verbindings asook 'n verdere 63 verbindings is in lammerwol geïdentifiseer. Die meerderheid van hierdie verbindings is reeds voorheen in verskeie soogdierafskeidings gevind. Die studie het verskeie interessante aspekte van hierdie semiochemiese kommunikasie aan die lig gebring. Eerstens is daar gevind dat die samestelling van die vlugtige organiese materiaal in die wol van tweelinglammers, oftewel hul reukprofiele, feitlik identies is. Verder verskil die reukprofiele van 'n tweeling van dié van ander tweelinge en enkelinge in die trop. Tweedens is gevind dat die reukprofiel van 'n lam nie by geboorte vasgelê word en so behoue bly nie, maar dat dit geleidelik verander oor ten minste die periode van sewe dae waaroor hierdie verskynsel bestudeer is. Dit noodsaak die ooi om haar geheue met betrekking tot die lam se reuk voortdurend te verfris gedurende die tydperk wat sy hoofsaaklik van haar reuksin gebruik maak om haar lam te herken. Derdens is die amniotiese vloeistof ondersoek as moontlike bron van ‘n sogenaamde moedermerk, waardeur chemiese mengsel van verbindings wat in ‘n spesifieke kwantitatiewe samestelling by geboorte deur die ooi op haar lam agter gelaat word. Ten opsigte van kwalitatiewe en kwantitatiewe samestelling, verskil die vlugtige organiese fraksie van die amniotiese vloeistof van die tweelinglam wat eerste gebore word van die amniotiese vloeistof van die lam wat tweede gebore word. Dit is onwaarskynlik dat amniotiese vloeistowwe wat ten opsigte van hul vlugtige organiese fraksies van mekaar verskil, nagenoeg identiese moedermerke op tweeling lammers sou kon laat. Vierdens is vasgestel dat spore van ses proteïene uit die amniotiese vloeistof op die wol van lammers agtergelaat word. Daar kon ongelukkig nie vasgestel word of hierdie proteïene 'n rol in die vrystelling van semiochemiese inligting speel nie. Gedragstoetse wat tydens die lamseisoen van 2009 uitgevoer is, het bevestig dat die lam se reukprofiel deurslaggewende rol in ooi-lam herkenning speel, maar gedragstoetse wat met sintetiese feromoonmengsels uitgevoer is, het onbesliste resultate opgelewer.
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Dougherty, Martin James. "Semiochemical mediation of oviposition by the phlebotomine sandfly Lutzomyia longipalpis (Diptera: Psychodidae)." Thesis, University of Liverpool, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241485.

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Fisher, Paul. "Responses of the blowfly Lucilia sericata (Miegen) (Diptera: Calliphoridae) to semiochemical baits." Thesis, University of Bristol, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247201.

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Yaman, Khatijah. "Semiochemical mediated oviposition and mating in Phlebotomus argentipes (Diptera: Psychodidae) sand flies." Thesis, Keele University, 2016. http://eprints.keele.ac.uk/2445/.

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Phlebotomus argentipes (Diptera: Psychodidae) is an important vector responsible for the transmission of Leishmania donovani that causes visceral leishmaniasis (VL) or kala-azar, in the sub-continent of India. The aims of this study were to investigate the semiochemicals that mediate oviposition and mating behaviour and also the courtship behaviours in P. argentipes. The result of ovipositional behaviour bioassays shows gravid P. argentipes females preferred to oviposit their eggs in the present of conspecific eggs and also eggs extract. This suggests the presence of an oviposition pheromone on the surface of the eggs which can be removed by washing with an organic solvent and transferred to an alternative surface. A Y-tube olfactometer was used to test an upwind anemotactic response of virgin females to male headspace volatiles and male extract, in the presence or absence of host odour. The results strongly suggest that a volatile maleproduced sex pheromone is present in P. argentipes. The results also suggest that under certain circumstances of the age of males and females and the presence of host odour, the females are attracted to live male and male extract of P. argentipes. Thus, presence of host odour might have a synergistic effect on the male-produced sex pheromone. Quantitative description and detailed of courtship behaviour(s) in both males and females of P. argentipes were observed. The results show that male behaviours during courtship are vital for the success of the mating. These predictor behaviours include approach wingflapping, abdomen bending and copulation attempt by male P. argentipes. Understanding of the biology, ecology and chemical mediated behaviour in P. argentipes will enhance and widen the knowledge leading to the improved of the efficiency and efficacy of the current sand fly control programmes.
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Martel, John W. "Development of Semiochemical-Based Strategies for Management of Colorado Potato Beetle, Leptinotarsa decemlineata (Say)." Fogler Library, University of Maine, 2004. http://www.library.umaine.edu/theses/pdf/MartelJW2004.pdf.

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8

Salom, Scott Michael. "Dispersal and flight behavior of Trypodendron Lineatum (Olivier) (Coleoptera: Scolytidae) as influenced by semiochemical and environmental factors." Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/29276.

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Laboratory bioassays using a wind tunnel were developed to study flight behavior and orientation of the striped ambrosia beetle, Trvpodendron lineatum (Olivier). Factors that were studied in detail were windspeed, semiochemical concentrations, and semiochemical combinations. In the first of two experiments examining the effect of wind speed on T. lineatum response to a semiochemical-baited substrate, the highest % of males (21.4) and females (25.3) caught in a funnel trap, occurred at 0.0 m/s. As windspeed was increased from 0.0 to 0.9 m/s, the percent of beetles caught decreased linearly for both sexes. A second experiment showed that in the presence of wind, responding beetles oriented anemotactically to the semiochemical-baited substrate. With wind absent, beetles flew randomly and erratically. Upon reaching close to the baited substrate, a greater proportion of the beetles responded to the chemical stimuli and landed on the substrate than when an airflow was present. These results suggest that T. lineatum are capable of responding under varied wind conditions typically present in a forest, whereby they use wind to orient to olfactory stimuli, yet are best arrested to the stimuli under still conditions. Flight response of T. lineatum to a multiple funnel trap baited with ethanol (1° attractant) and lineatin (2° attractant) at different release rates, indicated that only lineatin was effective in attracting beetles to this kind of trap. Maximum response by both males and females occurred at release rates of lineatin between 8 and 64 ug/24 h. However, in a more detailed study of T. lineatum response to ethanol and lineatin using modified drainpipe traps, serving as a model of a host tree, ethanol did positively influence male flight type, speed of reaction, and direction. Nevertheless, lineatin was the most important semiochemical in attracting males to land on and enter the traps. Ethanol was more important for females than for males, and when combined with lineatin, provided the optimal stimuli for attracting females to land on and enter the traps. Population movement of spring dispersing T. lineatum was studied using mark-recapture techniques with lineatin-baited funnel traps. In a first set of studies conducted in an even-aged second-growth coastal forest in British Columbia, beetle recapture distribution was compared with wind direction at distances between 5 and 500 m from the beetle release site. At 5 and 25 m, beetle recapture was predominantly upwind. With traps placed only at 100 m from the release site, beetles were recaptured in all directions irrespective of wind. However, with traps placed only 500 m from the release site, beetles were only recaptured in the downwind traps. In mark-recapture experiments conducted in a valley, beetles released from a forest margin influenced by prevailing up-valley winds, flew upwind within the forest to lineatin-baited funnel traps placed 25 m from the release site. Beetle recapture in an open setting was higher along the edge of the open setting than in its center, 325 m closer to the release site. Beetles were recaptured 1 km down-valley (upwind) and 1.9 km up-valley (downwind) from the release site. In one experiment (two releases), 10.6 and 7.8% of the marked beetles recaptured were collected in traplines ≥ 700 m and ≥ 1 km from the release site, respectively. In additional mark-recapture experiments in the valley, beetles were released simultaneously from a windward and leeward side of a forest margin in the valley through two experiments of four releases each. With long distance flight emphasized and no semiochemical-baited traps placed within 200 m of either release site, population movement was predominantly downwind. Beetles also flew across the valley to traps on the opposite facing slope at a fairly high frequency (38% of the recaptured beetles), during the first experiment. Beetles were recaptured at a much higher frequency in traps placed within a forest as compared to those in an open setting. This was likely a result of the calmer wind conditions under the forest canopy, facilitating better flying conditions and response to olfactory stimuli for the beetles. The implications these findings have on the general knowledge of scolytid beetle dispersal and orientation to olfactory stimuli are discussed. New considerations toward improving pest management strategies for T. lineatum as a result of these sets of studies are presented.
Forestry, Faculty of
Graduate
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Grosman, Donald Michael. "Southern pine beetle, Dendroctonus frontalis Zimmermann (Coleoptera: Scolytidae) : quantitative analysis of chiral semiochemicals /." Diss., This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-05042006-164540/.

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Krupke, Christian Harald. "Behavioural response of male codling moth, Cydia pomonella L., to a semiochemical-based attract-and-kill management strategy." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ51381.pdf.

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Schen-Langenheim, Greta Katherine. "Evaluation of Semiochemical Strategies for the Protection of Whitebark Pine Stands Against Mountain Pine Beetle Attack Within the Greater Yellowstone Ecosystem." DigitalCommons@USU, 2010. https://digitalcommons.usu.edu/etd/572.

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High-dose verbenone, verbenone plus nonhost volatiles (NHVs), and both semiochemicals in combination with aggregant-baited funnel traps were tested for stand- level protection against mountain pine beetle attack for two consecutive years (2004-2005) at three seral high elevation whitebark pine sites in the Greater Yellowstone Ecosystem. In 2004, two 0.25-hectare treatments comprised of 25 high-dose verbenone pouches or verbenone pouches combined with single baited funnel traps were tested in a push-pull strategy. In 2005, 25 high-dose verbenone and 25 NHV pouches, or verbenone and NHV in combination with baited funnel trap clusters were tested. In both years, treatments were compared to 0.25-hectare control plots with no semiochemicals or funnel traps. The proportion of trees attacked by mountain pine beetle in treated plots was significantly reduced, when compared to control plots, at only one site treated with verbenone in 2004, and at only one site in 2005. High-dose verbenone alone, verbenone and NHVs, and both semiochemicals combined with baited funnel traps in a push-pull strategy did not consistently reduce the proportion of mountain pine beetle attacked trees relative to control plots. No covariates tested, including stand density, beetle population size, or tree size were consistently significant in explaining proportion of trees attacked.
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Evenden, Maya L. "Semiochemical-based disruption of mate-finding behaviour in Choristoneura rosaceana (Harris) and Pandemis limitata (Robinson) (Lepidoptera: Tortricidae) in British Columbia apple orchards." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ37698.pdf.

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DeGomez, Tom, Christopher J. Fettig, Joel D. McMillin, John A. Anhold, and Christopher Hayes. "Managing Slash to Minimize Colonization of Residual Leave Trees by Ips and Other Bark Beetle Species Following Thinning in Southwestern Ponderosa Pine." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2008. http://hdl.handle.net/10150/146727.

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Pine Bark Beetles, THE PIÑON IPS BARK BEETLE, FIREWOOD AND BARK BEETLES IN THE SOUTHWEST, USING INSECTICIDES TO PREVENT BARK BEETLE ATTACKS ON CONIFERS, GUIDELINES FOR THINNING PONDEROSA PINE FOR IMPROVED FOREST HEALTH AND FIRE PREVENTION
Various techniques to reduce brood production of Ips and Dendroctonus spp. in ponderosa pine slash are discussed.
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Santangelo, Ellen M. "Stereoselective syntheses of semichemicals : Applications in ecological chemistry." Doctoral thesis, KTH, Chemistry, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-74.

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This thesis describes the syntheses of semiochemicals and their applications in the development of control methods for pest insects. The compounds synthesized are divided into three groups: 1) Lepidoptera pheromones; 2) methyl substituted chiral pheromones and 3) aphid pheromones.

Different purification techniques have been explored in order to provide > 99% pure semiochemicals for field tests. Examples of the techniques are uses of urea inclusion complexes, argentum chromatography, low temperature crystallization and what we call the Baeckström isolation technique.

Iridoids have been produced in a synthetic strategy including an intramolecular enal-enamine [4+2] cycloaddition, a dynamic acetylation and an enantioselective transesterification mediated by a lipase from Pseudomonas cepacia. The use of chiral auxiliaries to perform the intramolecular [4+2] cycloaddition has also been investigated. A useful asymmetric route to iridoids has been developed.

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Harder, Leroy. "Impact of the western balsam bark beetle, Dryocoetes confusus, at the Sicamous Creek research site, and the potential for semiochemical-based management in alternative silviculture systems." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq37542.pdf.

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Hitchner, Erin Marie. "Investigations of the integrated pest management of Colorado potato beetle, Leptinotarsa decemlineata (Say): Host plant preference, development of semiochemical-based strategies, and evaluation of a novel insecticide." Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/29562.

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Exploiting the chemical ecology of an insect can unveil novel strategies for its pest management. Though much has been learned about the chemical ecology of Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), a major pest of solanaceous crops in the U.S., there has been little use of this knowledge in pest management. To better understand host plant selection by CPB, field and laboratory-choice experiments were conducted in Virginia. In laboratory studies, CPB preferred potato over both tomato and eggplant foliage and eggplant over tomato foliage. However, field studies using counts of live beetles on untreated paired plants and counts of dead beetles on insecticide-treated plants revealed no significant preference for potato over eggplant. Additional studies showed that the presence of adult male CPB on foliage greatly impacted host plant selection, with significantly more adults being attracted to eggplant with male beetles than any other treatment combination. Adult CPB have been shown to be attracted to (S)-3,7-dimethyl-2-oxo-oct-6-ene-1,3-diol [(S)-CPB I], a male-produced aggregation pheromone. Field studies were conducted to determine if the opposite enantiomer of the pheromone, (R)-CPB I had an effect on CPB in the field. Results revealed no differences in counts of all CPB life stages between untreated potato plots with and without rows inundated with (R)-CPB I lures. In addition, the relative attraction of CPB adults to various racemic forms of the (S)- and (R)-enantiomers was also investigated and showed that racemic blends that were less than 97%(S) were not attractive to CPB adults. Combinations of the (S)-CPB I pheromone with synthetic plant volatiles consisting of (Z)-3-hexenyl acetate, (+)-linalool, and methyl salicylate were investigated in a trap crop strategy in potatoes, but failed to reduce CPB numbers in untreated middle rows of potatoes. Combinations of the (S)-CPB I pheromone with synthetic plant volatiles were also used in a novel CPB trap designed to catch colonizing adults in the field. Although the traps caught CPB adults, no differences were observed in traps baited with and without the attractant. Metaflumizone, a novel semicarbazone insecticide, was recently shown to be highly efficacious on CPB. Laboratory studies found the combination of metaflumizone and a low concentration (0.39 ppm) of the pyrethroid esfenvalerate was slightly synergistic on CPB adults and early (1st-2nd) instar larvae. Field trials combining a low rate of esfenvalerate and metaflumizone at one tenth the field rate controlled beetles as well as the full rate of metaflumizone.
Ph. D.
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Otienoburu, Philip E. "Plant Semiochemicals as Mosquito Attractants." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1313605670.

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Zabaras, Regina, University of Western Sydney, of Science Technology and Environment College, and of Science Food and Horticulture School. "The evolution of semiochemicals in Australian marsupials." THESIS_CSTE_SFH_Zabaras_R.xml, 2003. http://handle.uws.edu.au:8081/1959.7/759.

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The aim of this project was to study the nature and relative proportion of the volatile components in the sternal-gland secretions obtained from a wide range of Australian marsupials.The results obtained were then used to investigate the evolution of semiochemicals in Australian marsupials by using the current phylogenetic tree as a template.The initial part of the study was dedicated to the investigation of some of the techniques available for the sampling and analysis of gland secretions. Individuals from 8 families within the Marsupialia and 1 family from the Monotremata were sampled over an 18 month period.The obtained results were then subjected to multivariate statistical analysis followed by cladistic analysis.In several species the secretion composition was found to be affected by the breeding status of individuals for both genders.Many other factors such as animal-age, hierarchical status, diet,and lifestyle were also observed to affect the secretion composition. Finally, cladistic analysis demonstrated the differences in the levels of divergence at the species, familial and ordinal levels and highlighted secretion components that could be used to differentiate between super families, species and even sexual status of individuals.
Master of Science (Hons)
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Zabaras, Regina. "The evolution of semiochemicals in Australian marsupials." View thesis View thesis, 2003. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030402.151527/index.html.

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Thesis (M.Sc. (Hons.)) -- University of Western Sydney, 2003.
"A thesis presented in partial fulfilment of the requirements for the degree of Master of Science (Honours), College of Science, Technology and the Environment, University of Western Sydney ... January, 2003" Bibliography : leaves 142-150.
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Nordin, Ove. "Stereoselective synthesis of semiochemicals related to pine sawflies." Doctoral thesis, KTH, Chemistry, 1999. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-2852.

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This thesis describes the stereochemistry and charactericsof (–)-1,6-germacradien-5-ol, isolated from the larvaldefence substance of the pine sawflyNeodiprion sertiferand from the needles of Scots pine,Pinus sylvestris. The conformational behaviour of thissesquiterpene alcohol was investigated by molecular mechanicsstudies (MM2) and NMR. The absolute configuration at the twostereogenic centres was established as (5S,8S), after NOE measurements and chemical transformationinto (–)-α-cadinol and 1-endo-bourbonanol. Our studies towards a stereoselectivetotal synthesis of (–)-1,6-germacradien-5-ol using ringclosing metathesis (RCM) is also reported. However, allattempts to prepare this germacrene alcohol and other1,6-cyclodecadien systems using RCM failed.

Pseudomonas cepacialipase (PCL) catalysed acylation ofprimary 2-methylalcohols with vinyl acetate is anenantioselective reaction. The enantioselectivity of PCLtowards a series of primary 2-methylalcohols were studied. Highenantiomeric ratios,E>100, were observed for2-methyl-3-aryl-1-propanols, where aryl is 2-thiophene,3-thiophene, 2-furan and phenyl. In contrast the selectivitywas rather low for other 3-substituted primary2-methylpropanols such as 3-alkyl and 3-cycloalkyl, E ≈10 - 20. When moving the thiophene ring closer or further awayfrom the stereogenic centre a dramatic decrease in E wasobserved. 2-Isopropyl-5-methyl-5-hexen-1-ol, a possiblebuilding block for the total synthesis of1,6-germacradien-5-ol, was also successfully resolved with PCL,E= 14.

Keywords:defence substance, 1,6-germacradien-5-ol,Neodiprion sertifer,Pinus sylvestris, molecular mechanics, configuration,metathesis, RCM, stereoselective, kinetic resolution,transesterification, lipase,Pseudomonas, PCL, 2-methylalcohol, 2-isopropylalcoholenantioselective.

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Santangelo, Ellen M. "Stereoselective syntheses of semiochemicals : applications in ecological chemistry /." Stockholm : Organic Chemistry, Department of Chemistry, Royal Institute of Technology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-74.

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22

Meade, Brian J., and mikewood@deakin edu au. "Semiochemicals in merino ewes: Field effects and chemical identification." Deakin University. School of Sciences, 1986. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20050815.112723.

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23

Gurney, Joanne Elizabeth. "The use of semiochemicals for vertebrate pest population control." Thesis, University of York, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273829.

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Henry, Elizabeth Judith. "The synthesis of insect sex pheromones." Thesis, Bangor University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.481279.

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Nilsson, Anna. "Identification and Syntheses of Semiochemicals Affecting Mnesampela privata and Trioza apicalis." Licentiate thesis, Mid Sweden University, Department of Natural Sciences, Engineering and Mathematics, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-10596.

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The Autumn gum moth, Mnesampela privata (Lepidoptera: Geometridae) is an endemic Australian moth whose larvae feed upon species of Eucalyptus. The moths favorite host plants are E. globulus and E. nitens which are the most important species used in commercial plantations of the Australian pulpwood industry. The autumn gum moth has become one of the most significant outbreak insects of eucalyptus plantations throughout Australia. As a consequence great financial losses to the forest industry occur. Today insecticides such as pyrethroids are used for control of eucalyptus defoliators as M. privata.

The carrot psyllid, Trioza apicalis (Homoptera: Psylloidea), is one of the major pests of carrot (Daucus carota) in northern Europe. The psyllid causes curling of the carrot leafs and reduction of plant growth. Today the carrot crops are protected with the pyrethroid insecticide cypermethrin, which is toxic to aquatic organisms and is, from 2010, prohibited for use in Sweden by the Swedish Chemicals Inspectorate.

An alternative to insecticides is to protect the seedlings with semiochemicals, a chemical substance or mixture of them that carries a message. This thesis describes the identification and the syntheses of semiochemicals from the above mentioned insect species.

From analysis of abdominal tip extracts of M. privata females from Tasmania a blend of (3Z,6Z,9Z)-3,6,9-nonadecatriene and (3Z,6Z,9Z)-3,6,9-heneicosatriene was identified as the sex pheromone of this species. The identification of the C19- and C21-trienes was confirmed by synthesis.

In the analysis of carrot leaf extracts we found a compound, α-cis-bergamotene, that induces antennal response in the carrot psyllid. This is just the beginning of the studies of trying to manipulate this psyllid with semiochemicals instead of insecticides.

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Hayes, Richard Andrew, of Western Sydney Hawkesbury University, Faculty of Science and Technology, and School of Science. "Semiochemicals and social signalling in the wild European rabbit (Oryctolagus cuniculus(L.)." THESIS_FST_SS_Hayes_R.xml, 2000. http://handle.uws.edu.au:8081/1959.7/371.

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The European rabbit lives in defined social groups of between two and about twenty individuals. There are distinct social hierarchies within each group. Rabbits are known to scent-mark their environment with secretions from several glands, and the secretion of the submandibular cutaneous gland is strongly correlated with social status. Dominant, male rabbits have a higher secretory activity of the gland, and show much more scent-marking behaviour than do any other individuals within the social group. This study was principally conducted at Hope Farm, Cattai National Park in New South Wales, Australia.The proteinaceous components of the secretion varied between individuals, but the protein profile of an individual did not change over time.It was found that dominant rabbits chin mark preferentially at the entrances to warrens, and at the boundaries of their territory.The work in this study provides new insights into the way that rabbit semiochemical messages work. The difference between the secretion of a subordinate and a dominant rabbit appears to be due to the presence or absence of one compound, 2-phenoxy ethanol. This compound, with known fixative properties, supports the idea that the only difference between dominant and subordinate secretions is whether or not they persist in the environment after marking. Such a mechanism for asserting dominance may be much more common in mammals than is apparent from the published literature
Doctor of Philosophy (PhD)
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Hayes, Richard Andrew. "Semiochemicals and social signalling in the wild European rabbit (Oryctolagus cuniculus (L.)) /." View thesis View thesis, 2000. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030424.112701/index.html.

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Thesis (Ph.D.) -- University of Western Sydney, Hawkesbury, 2000.
A thesis presented to the University of Western Sydney, Hawkesbury, in partial fulfilment of the requirements for the degree of Doctor of Philosophy, December, 2000. Includes bibliographical references.
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Curtiss, Robert T. "Attractiveness of semiochemicals to green lacewings for biological control in pome fruit." Online access for everyone, 2008. http://www.dissertations.wsu.edu/Thesis/Spring2008/R_Curtiss_050808.pdf.

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Buteler, Micaela. "Integrated management of the Wheat Stem Sawfly by exploiting semiochemicals to enhance trap crops." Thesis, Montana State University, 2008. http://etd.lib.montana.edu/etd/2008/buteler/ButelerM0508.pdf.

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The wheat stem sawfly, Cephus cinctus Norton (WSS) causes significant damage in cereal crops in the northern Great Plains of North America. Recently, the use of winter wheat as a trap crop to protect spring wheat from this insect pest in a wheat-fallow cropping system was evaluated, yielding promising results. Subsequently, the overall objective of this dissertation research was to improve the efficacy of winter wheat trap crops to manage the WSS. Oviposition behavior studies in the presence of hosts infested by conspecifics showed that WSS did not avoid infested hosts. These results confirmed the potential of a trap to provide a sink for multiple eggs, resulting in increased WSS mortality due to cannibalism. I identified suitable winter wheat cultivars based on agronomic characteristics that influence WSS behavior in conjunction with the emission of behaviorally active plant volatiles, as well as the performance of the cultivars in the area where the pest occurs. Results from this study identified five cultivars, Norstar, Morgan, BigSky, Neeley, and Rampart, with good potential as trap crops. Norstar emitted greater amounts of attractive volatile compound ß-ocimene, and was the preferred host in greenhouse choice tests. Based on these results, a perimeter trap cropping trial comparing three winter cultivars as traps (Norstar, Neeley and Rampart) to protect spring wheat was conducted for two consecutive years. Two spring wheat cultivars differing in suitability for infestation by sawflies were chosen as the main crop. WSS abundance was significantly greater in the winter wheat traps than in the adjacent unattractive spring cultivar Conan both years of the experiment and greater than an attractive spring cultivar Reeder in 2005. No differences in infestation were observed between winter cultivars, although greater numbers of eggs were found in Norstar than in Rampart traps. Swathing the trap crop before grain fill killed most larvae developing in the trap crop. Finally, I investigated the effect of a synthetic attractive compound, (Z)-3-hexenylacetate, on oviposition and found that application of this compound in a lanolin paste resulted in increased oviposition by females in greenhouse choice tests. The results obtained suggest that a trap cropping management strategy involving attractive and unattractive cultivars, and semiochemically assisted trap cropping by application of synthetic host volatiles, show potential to manage the WSS.
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Chinta, Satya Prabhakar [Verfasser], and Stefan [Akademischer Betreuer] Schulz. "Identification and synthesis of semiochemicals from arthropods / Satya Prabhakar Chinta ; Betreuer: Stefan Schulz." Braunschweig : Technische Universität Braunschweig, 2010. http://d-nb.info/1175828076/34.

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31

Burhani, Joseph. "Role of semiochemicals in oviposition and mating behaviour of Aedes aegypti (Diptera: Culicidae)." Thesis, Keele University, 2013. http://eprints.keele.ac.uk/194/.

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Aedes aegypti (Diptera: Culicidae) is the major vector of a number of arboviruses including dengue. Understanding how semiochemicals might mediate the key behaviours of mating and oviposition should lead to a better understanding of the biology of Aedes aegypti and might also lead to practical vector control applications. The results of behavioural investigations into putative egg associated oviposition pheromone have been contradictory and incomplete in that they failed to control numbers of eggs in their experimental design. A previous study found behavioural evidence for a male produced sex pheromone, but an upwind anemotactic response of females was not tested and it could be argued that the experimental design was not robust. For this thesis no-choice and choice bioassays were carried out to test the oviposition response of gravid females to both specific numbers of con-specific eggs and methanol extract of eggs. An olfactometer was designed to test the upwind anemotactic response of virgin females to male headspace volatiles with and without host odour cues. These male odours were also used to bait BG-sentinel traps in the field. While no evidence was found that was consistent with an egg associated oviposition pheromone in Aedes aegypti, results from both laboratory and field based experiments suggest that males might emit a pheromone in response to host odour that attracts virgin females. Results from experiments in which males were not exposed to host odour suggest that host odour might be required to stimulate pheromone release.
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Garraway, Richard. "The action of semiochemicals on olfactory nerve activity and behaviour of Deroceras reticulatum (Mull)." Thesis, University of Portsmouth, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303955.

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Tarver, Matthew Robert. "Influence of soldier derived semiochemicals on Reticulitermes flavipes worker caste differentiation and gene expression." [Gainesville, Fla.] : University of Florida, 2009. http://purl.fcla.edu/fcla/etd/UFE0025142.

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34

Losey, Stephen M. "Orientation and dispersal of Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae) in response to various semiochemicals." Thesis, Kansas State University, 2015. http://hdl.handle.net/2097/20566.

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Master of Science
Department of Entomology
Thomas W. Phillips
The rusty grain beetle, Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae), is a very common worldwide pest of stored grains. The orientation of C. ferrugineus beetles to various semiochemicals was studied in both the laboratory and field. In laboratory experiments glass two-choice pitfall bioassay dishes were used. Mixed-sex populations of beetles responded positively and significantly to cucujolide I and II separately and in combination compared to controls. Bioassays using the two aggregation pheromones of the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae). Dominicalure 1 and 2 together elicited unexpected significant attractive responses by C. ferrugineus as did assays with the synthetic pheromones from other species. Bioassays showed that C. ferrugineus were not attracted to either corn meal or rolled oats, but they were attracted to commercial grain-based lures and also to ethanol, a natural fermentation product from grains. Several bioassays were conducted to test the attractiveness of naturally produced beetle volatiles to C. ferrugineus, but these showed no orientation to volatiles from either the beetles or their food only. Field tests were conducted in Kansas to test attractiveness of the synthetic pheromones cucujolide I and II in lures together with wheat versus wheat only as a control using Lindgren funnel traps. Field tests in 2014 with cucujolide II pheromone lures showed a significant response by feral C. ferrugineus when tested against wheat. Other field tests to examine dispersal of C. ferrugineus relative to grain storages showed that more C. ferrugineus were caught on the western side of grain bins compared to other cardinal directions at two different locations. Results from field and laboratory studies suggest that semiochemical-based tools can be developed to study dispersal behavior in field populations of C. ferrugineus.
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Banks, Glyn Raymond. "Analysis and identification of potential semiochemicals in the scent-markings of the tiger, Panthera tigris." Thesis, Anglia Ruskin University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313206.

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Liu, Youngbiao. "Biology of Gnathotrichus retusus and behavioural responses of G. retusus and G. sulcatus to semiochemicals." Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/26441.

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Gnathotrichus retusus is primarily univoltine with a minor fraction of the population taking more than one year to complete the life cycle. From the spring to the summer, the development of brood from egg to adult took about 40 days or more in Douglas-fir logs. Brood production was significantly related to the gallery length. Boring activities were not consistently related with temperature, shifting from shallow sapwood to deep sapwood over time. Fungal staining was usually limited to the wood near the gallery entrance, and became darker in colour over time beginning in June. Abandonment of some galleries mainly occurred in June and July by females, and was probably induced by high temperatures. G. retusus preferred Douglas-fir stumps to western hemlock stumps, but both host tree species were equally suitable for G. retusus brood development. Significant differences were found among individual Douglas-fir and western hemlock stumps in attack density and brood production. Within a stump, attack density and brood production for Douglas-fir, and attack density for western hemlock increased from the stump top to the bottom. G. retusus emergence from Douglas-fir and western hemlock stumps and G. retusus and G. sulcat us flights began in late April when the daily maximum temperature reached 13.5°C, and peaked in late May. Brood emergence of G. retusus ceased, with rare exception, in late June. G. retusus had only one big peak flight while G. sulcatus had a small second peak flight in late July. Seasonal flights ceased in October when weekly mean maximum temperatures dropped below 15°C. Brood emergence, seasonal flights, and the sex ratios of brood ready to emerge and captured flying beetles were positively correlated with maximum temperature. G. retusus had a bimodal diurnal flight rhythm: a very small morning flight and a much larger dusk flight. Light intensity seemed to be a major stimulus in initiating the flight. However, diurnal flight might also be influenced by both temperature and relative humidity. Both G. retusus and G. sulcatus of both sexes responded significantly to ethanol or their own aggregation pheromones, (+)-sulcatol and (±)-sulcatol respectively, and ethanol was a synergist of (+)-sulcatol for G. retusus of both sexes. Alpha-pinene was neither a primary host attractant nor a synergist of aggregation pheromones. The sex ratios (female/male) of both species increased significantly from less than one for host chemicals alone to above one for treatments including aggregation pheromones. The sex ratio of G. sulcatus increased with increases in release rates of (±)-sulcatol.
Forestry, Faculty of
Graduate
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Bouwer, Marc Clement. "Identication of semiochemicals from four major insect pests of Eucalyptus and Pinus species in South Africa." Thesis, University of Pretoria, 2014. http://hdl.handle.net/2263/78160.

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The chemical ecology for key insect pests in South Africa's commercial Pinus and Eucalyptus plantations are explored in this thesis. The main aim was to discover and characterize semiochemical compounds that explain certain behaviours of the insects involved, and that could potentially be exploited in future for the manipulation of the insects' behaviour. Such formulations are sought after because they can be applied in environmentally friendly pest management techniques. Semiochemical interactions were studied in four di erent biological systems. These included the sex pheromone communication system for the Cossid moth, Coryphodema tristis; allelochemical interactions between the Eucalyptus weevil Gonipterus spp. and their Eucalyptus host; allelochemical interactions between Sirex noctilio's, symbiotic fungus, Amylostereum areolatum and its biological control agent Ibalia leucospoides; and allelochemical interactions between the egg clutches of Thaumastocoris peregrinus and its biological control agent Cleurocoides noackae. Semiochemical compounds were found and identi ed through analysis techniques that included gas chromatography coupled to electroantennography (GCEAD) and gas chromatography coupled to mass spectrometry (GC-MS). Some of these semiochemical interactions were complex involving combinations of di erent chemical cues, such as the host recognition cues identi ed for Gonipterus species and potential cues between T. peregrinus females and their egg clutches. Other speci c interactions were found to be simpler and relied on a few speci c chemicals. These included the sex pheromone communication between C. tristis adults and the interaction occurring between female I. leucospoides wasps and the mutualistic fungus of their prey, namely A. areolatum. Biological activity was investigated only for compounds with con rmed identity and included the sex pheromones of C. tristis and some of the chemicals identi ed from the egg clusters of T. peregrinus. These tests were conducted in laboratory and eld conditions. Biological activity was proven for the identi ed sex pheromone of C. tristis during eld trials conducted in 2011 and 2013. One of the chapters was published and another submitted for publication in a peer reviewed journal. Two provisional patents were also registered from this work.
Thesis (PhD)--University of Pretoria, 2014.
Chemistry
PhD
Unrestricted
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Hull, Mark Q. "The role of semiochemicals in the behaviour and biology of Lepeophtheirus salmonis (Kroyer, 1837) : potential for control?" Thesis, University of Aberdeen, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310772.

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The role of semiochemicals in the behaviour and biology of Lepeophtheirus salmonis was investigated using a range of techniques. The potential use of semiochemicals in the behavioural ecology of mobile stages was examined using longitudinal monitoring and experimental manipulation of laboratory reared single cohort populations. The chronic and long term effects of separation from the host were also investigated using similar populations. The nature and chemosensory capability of the sense system of the parasite was assessed through morphological and ultrastructural studies. Finally, the nature of potential chemical stimuli during initial copepodid settlement, pair formation and mating, and host re-attachment of mobile stages, was examined using both in vitro and in vivo techniques. Longitudinal monitoring of populations created a model for mobile development and the timing and processes of pair formation and mating. There was evidence of a hierarchy of pair formation between female stages, periods of strong mate competition between males, and many factors within the processes were defined. Survival off the host was strongly related to the developmental stage and/or size of the louse; with adult females surviving for the longest and preadult I males for the shortest periods. The ability of adult males to re-attach and subsequently persist on the host was significantly reduced after only 72 hours of separation. Very few potential chemosensory setae were found on the appendages examined, the exception to this being the antennule. Two distinct populations of setae on the distal (14 setae) and proximal (27 setae) articles of the antennule demonstrated a wide range of morphology. The internal organisation, innervation and ultrastructure of these antennular setae was examined in detail. The setae could be divided into at least 6 distinct categories, when the internal data were combined with the external morphology.
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Kirkland, Dean Lee. "The use of semiochemicals to enhance the natural control of pests of arable crops by invertebrate predators." Thesis, University of Edinburgh, 1999. http://hdl.handle.net/1842/28368.

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The electrophysiological and behavioural responses of the aphidophagous hoverfly Episyrphus balteatus Degear, and polyphagous ground beetles Pterostichus melanarius Illiger and Nebria brevicollis Linneaus, to a range of volatile semiochemicals were studied. Phacelia tanaectfiolia flower extract, Nepeta cataria whole plant extract, and (E)-β-farnesene where found to be attractive to the predators in laboratory and windtunnell assays. Field trials demonstrated that the attractive semiochemicals could be placed in dispensers in arable crops to increase the amount of predators present throughout the field system. There was also a corresponding decrease in the number of pest species present in the treated field plots relative to the control plots. Phacelia flower extract was found to have the greatest effects on predator and prey numbers. The mechanisms of the reduction in prey numbers were studied using exclusion experiments in the field and enzyme linked immunosorbant assays on the gut contents of the predators. There was found to be a link between the increased rates of predation in the field and the decline in pest numbers. The potential of semiochemicals to enhance natural control of crop pests is discussed.
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Ukeh, Donald A. "The identification and use of semiochemicals for the control of the maize weevil, Sitophilus zeamais (Motschulsky) in Nigeria." Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources, 2008. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=25167.

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Dodds, Catherine Jane. "The action of naturally-occuring semiochemicals on feeding behaviour and neurophysiology of the field slug Deroceras reticulatum (Mueller)." Thesis, University of Portsmouth, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310443.

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42

Costa, Arnaud. "Aggregation, dispersal and edge behavior of the bark beetle predator Thanasimus dubius (Coleoptera: Cleridae); potential use in biological control." OpenSIUC, 2010. https://opensiuc.lib.siu.edu/dissertations/129.

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Bark beetles are major pests of pine forests in North America that can inflict considerable damage and cause severe economic loss. The checkered beetle Thanasimus dubius Fabricius (Coleoptera: Cleridae), an abundant predator in the Eastern USA and Canada, has been suggested to influence the dynamics of several bark beetles, including the economically important southern pine beetle (SPB), Dendroctonus frontalis Zimmermann (Coleoptera: Curculionidae). Because of the importance of T. dubius in pine forests, I studied several aspects of T. dubius biology including both its chemical and dispersal ecology. I first present an experiment that was conducted to improve the rearing system of T. dubius so that sufficient numbers of predators could be produced more efficiently for both behavioral and ecological studies. Improvements to the rearing method potentially could be achieved by adding a preservative to increase the shelf-life of the diet used to feed larval T. dubius thereby allowing feeding intervals to be extended. To evaluate this, I added sorbic acid, a preservative, to the larval diet at three different concentrations (0, 0.1 and 0.2%) and for two different intervals between feedings (2-3 vs. 5 days). Additionally, I measured potential deleterious effects of this preservative on predator performance (i.e., female fecundity). I then assessed the effect of this predator on SPB survival by releasing newly hatched T. dubius larvae at several densities (0, 50 100, and 200) on pine logs infested by SPB. I also studied the chemotactic response of this predator toward various volatiles such as prey pheromones or tree volatiles in a wind tunnel. I developed a method that associated upwind flight behavior and antennal behavior to quantify the relative attractiveness of each tested source of chemical. I then conducted three experiments to investigate the ability of individual T. dubius to respond to different prey olfactory signals (bark beetle pheromones) and assess their potential for learning. First, I examined individual predator preferences toward three major prey pheromones (ipsenol, ipsdienol, and frontalin) in a study that combined a mark-release-recapture experiment with a field choice test. I also measured the responses of individual wild T. dubius in a wind tunnel, which allowed the testing of a wider range of semiochemicals (frontalin, ipsenol, ipsdienol, sulcatol, and α-pinene). A final wind tunnel experiment tested the ability of naive predators to learn two prey pheromones, frontalin and ipsenol, that were presented alone or associated with a reward. In the last chapter, I quantified the dispersal of this predator and its behavior along an edge separating a pine forest from a non-suitable habitat. I analyzed T. dubius distribution and movement in the field relative to its bark beetle prey Ips grandicollis Eichhoff (Coleoptera: Curculionidae) and to the root feeder Dendroctonus valens LeConte (Coleoptera: Curculionidae). These three insects are associated with the phenomenon of red pine decline in the Great Lakes area. Thus, understanding the relative pattern of movements of these three beetles could provide considerable knowledge on the spatial and temporal progression of red pine decline by, for instance, assessing the connection between existing pockets. I estimated the dispersal quantiles for this predator relative to its bark beetle prey and determined whether dispersal behavior was relatively homogeneous (one kind of disperser) or heterogeneous (two kinds). In a second part, I sampled the abundance of T. dubius, I. grandicollis, and D. valens along transects set between a matrix area constituted by a clearing and a habitat zone composed of red pine forest. I further developed a diffusion model, including a constant k (corresponds to the ratio of densities along the edge), that permits characterization of beetle behavior around the boundary. Studies developed in the present dissertation, therefore, investigated several aspects of T. dubius ecology: predation on SPB, ability to respond to an olfactory signal, and dispersal traits. I first showed that augmentation with larval T. dubius can successfully reduce the SPB ratio of increase in infested pine logs. I also developed a system of rearing T. dubius that was more efficient and could allow larger numbers of predators to be produced. Sorbic acid did not reduce adult lifetime or size but did affect female fecundity (20 - 40% reduction). Increasing feeding time interval to 5 days (instead of 2-3 days) improved the efficiency of the system, even when sorbic acid was not added in the diet. Wind tunnel experiments present a methodology that could enable future quantification of the relative attractiveness of various semiochemical treatments. I identified a particular antennal behavior, which I called "stand up antennal" that was typically produced when the insect was attracted to a semiochemical. The choice tests in the field and the wind tunnel experiment using wild adults both showed that T. dubius individuals are generalists that are flexible in their response to a broad range of semiochemical signals (frontalin, ipsenol, ipsdienol, sulcatol, and α-pinene). I demonstrate that naive predators are more attracted toward ipsenol after having experienced conditioning with this kairomone via a reward. Finally, experiments on dispersal and edge behavior revealed that T. dubius and one of its common prey, the bark beetle I. grandicollis, exhibit a different pattern of movement within red pine stands and surrounding habitats. First, adult T. dubius can disperse substantially further (50% dispersed beyond 1.54 km) than I. grandicollis adults (50% dispersed beyond 0.13 km). Second, T. dubius was highly affected by the presence of an edge, showing a step-like pattern with very predators caught in unsuitable areas. Conversely, the behavior of I. grandicollis was less limited by such a boundary. As with T. dubius, the root colonizer D. valens showed a strong edge behavior that was characterized by avoiding matrix zones.
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Jones, Perer R. H. "An investigation of the semiochemicals of the Mediterranean black scale Saissetia oleae and the olive bark beetle Phloeotribus scarabaeoides." Thesis, Cardiff University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491915.

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Okal, M. N. "Analysing the role of semiochemicals in the oviposition substrate choices of the malaria vector mosquito Anopheles gambiae sensu lato." Thesis, London School of Hygiene and Tropical Medicine (University of London), 2015. http://researchonline.lshtm.ac.uk/2528132/.

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The search for tools that target malaria vector that resist insecticides and bite outdoors has become a research priority. Such tools will be necessary for managing residual malaria transmission and hastening the eradication of this devastating disease. This study investigated chemicals that potentially affect the oviposition substrate choices of Anopheles gambiae sensu lato (s.l.). It is foreseen that increased knowledge of the oviposition behaviour of this major malaria vectors and chemicals cues that mediate oviposition site-selection can be applied in the development of additional sampling methods and alternative interventions that to trap gravid malaria mosquitoes outdoors. To achieve a reproducible high egg-laying success of An. gambiae sensu stricto (s.s.) and An. arabiensis four factors were evaluated: (1) the time provided for mating; (2) the impact of cage size, mosquito age and female body size on insemination; (3) the peak oviposition time; and, (4) the host source of blood meals. Then four bioassays were optimised for studying oviposition responses of An. gambiae s.s. in the laboratory and semi-field conditions: a WHO-tube bioassay and a wind-tunnel that detected short-range attraction in the laboratory; a two-tier choice egg-count bioassay that compared the relative proportion of eggs laid in substrates in the laboratory; and a modified BG Sentinel mosquito gravid trap that evaluated long-range attraction of gravid females to olfactory cues in the semi-field. Finally, the oviposition responses of gravid An. gambiae s.s. mosquitoes to water vapour, Bermuda grass hay infusion (hay infusion), and putative semiochemicals identified from the hay infusion and a soil infusion previously shown to elicit higher egg deposition compared to filtered Lake Victoria water (lake water) in two choice egg-count bioassays (Herrera-Varela et al. 2014), were evaluated. High oviposition rates [84%, 95% confidence interval (CI) 77-89%] were achieved when 300 male and 300 blood-fed female An. gambiae s.s. were held together in a cage for four days. The chance of oviposition in the mosquitoes dropped when human host source of blood-meal was substituted with a rabbit (Odds ratio (OR) 0.30, 95% CI 0.14-0.66) but egg-numbers per female were not affected. All four optimised oviposition bioassays effectively showed between 15-20% shifts in oviposition substrate choices of mosquitoes with 80% statistical power and 5% significance. Using the WHO-tube bioassay, gravid An. gambiae s.s. were shown to be 2.4 times (95% CI 1.3-4.7 times) more likely to move towards high humidity in still air compared to non-gravid Preamble mosquitoes. This was more pronounced in the airflow olfactometer where the gravid mosquitoes were 10.6 times (95% CI 5.4-20.8 times) more likely to fly into a chamber with water than a dry chamber. Two-choice egg-count bioassays showed that An. gambiae s.s. were less likely to lay eggs in six-day old hay infusion (OR 0.10, 95% CI 0.03-0.33) compared to lake water. Ten putative semiochemicals were identified from the hay infusion using mass spectrometry and published electrophysiology data: 4-hepten-1-ol, 4-ethylphenol, phenylmethanol, 2-phenylethanol, indole, phenol, 3-methylindole, 3-methyl-1-butanol, 4-ethylphenol, and nonanal. Tested in two-choice egg-count bioassays, the first four listed compounds had no effect on egg deposition at the tested concentrations (between 0.01-5 parts per million) but mosquitoes were less likely to lay eggs in at least one concentration of 3-methylindole (OR 0.39, 95% CI 0.21-0.71), indole (OR 0.57, 95% CI 0.37-0.87), 3-methyl-1-butanol (OR 0.32, 95% CI 0.22-0.47), phenol (OR 0.55, 0.32-0.95), 4-methylphenol (OR 0.32, 0.18-0.57) and nonanal (OR 0.66, 95% CI 0.47-0.91) compared to lake water. In contrast to the hay infusion and hay infusion volatiles, An. gambiae s.s. were about two times more likely to lay eggs in cedrol, a sesquiterpene alcohol identified from the soil infusion, compared to lake water (OR 1.84, 95% CI 1.16-2.91). Cedrol attracted twice as many gravid mosquitoes in the semi-field also (OR 1.92, 95% CI 1.63-2.27). In the field, modified BG-Sentinel traps, electrocuting nets and OviART gravid traps with lake water and cedrol were three times more likely to trap malaria mosquitoes compared to traps with water only (OR 3.3, 95% CI 1.4-7.9). In conclusion, water vapour was shown to be a strong, non-specific pre-oviposition attractant for gravid An. gambiae s.s. in still air and moving air. It is probably the long range cue that gravid An. gambiae s.l. use to detect the presence aquatic habitats beyond the range of chemical cues. Evidence showed that An. gambiae s.s. discriminate between potential oviposition substrates and that this selective process is in-part mediated by volatile organic compounds originating from the site. Water vapour leads gravid mosquitoes to aquatic sites but semiochemicals enable the mosquitoes to discriminate and select between potential habitats. It was demonstrated that synthetic equivalents of semiochemicals found to attract gravid mosquitoes such as cedrol can be used to trap malaria mosquitoes outdoors.
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45

Favaris, Arodí Prado. "Isolamento do cairomônio de Anagasta kuehniella Zeller (Lepidoptera: Pyralidae) responsável pela atração do parasitoide Habrobracon hebetor Say (Hymenoptera: Braconidae)." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-23012017-152532/.

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Cairomônios são semioquímicos envolvidos nas interações interespecíficas dos insetos, que beneficiam o receptor em detrimento do emissor. Uma destas interações envolve a busca hospedeira por parasitoides, que detectam estes compostos como estratégia para localizar seus hospedeiros. No caso do ectoparasitoide larval, Habrobracon hebetor Say (Hymenoptera: Braconidae), o \'frass\' de Anagasta kuehniella Zeller (Lepidoptera: Pyralidae) libera um cairomônio que atrai as fêmeas do parasitoide. Considerando que A. kuehniella é muito utilizada para produção de ovos, visando à criação de inimigos naturais, este cairomônio é indesejável, pois acaba favorecendo altas infestações por H. hebetor, podendo causar prejuízos expressivos ao longo do processo. Uma das soluções para o controle de tais infestações poderia ser o emprego de armadilhas com o semioquímico sintético. Entretanto, como o cairomônio ainda não foi identificado, este trabalho teve como objetivo o seu isolamento - a etapa inicial para sua identificação. O cairomônio foi extraído por meio da lavagem com solvente e aeração do \'frass\' de A. kuehniella. Os extratos foram, então, testados em olfatometria de quatro vias com fêmeas do parasitoide, registrando-se o tempo de permanência em cada tratamento. O extrato de lavagem ativo foi fracionado em coluna de sílica em cinco frações, cuja atratividade também foi averiguada para proceder com o isolamento do cairomônio. Os extratos e frações foram então analisados por cromatografia gasosa por ionização em chama (GC-FID) e espectrometria de massas (GC-MS), a fim de localizar compostos exclusivos nas amostras ativas. Além disso, as frações provenientes do extrato de lavagem foram aeradas para a extração de seus compostos voláteis e também analisadas por GC-MS. O cairomônio foi isolado na fração 75% éter, indicando ser um composto polar. Por comparação dos cromatogramas, apenas um pico na coluna HP-5ms foi selecionado como pertencente ao cairomônio. Em coluna Rtx-1ms, o pico bifurcou-se, indicando que, pelo menos, um dos compostos faz parte do cairomônio. As combinações metodológicas deste trabalho conduziram ao isolamento do cairomônio presente no \'frass\' de A. kuehniella e à seleção de pelo menos um composto que compõe o semioquímico responsável pela atração do parasitoide H. hebetor, resultando nas primeiras informações de sua estrutura química para sua futura identificação.
Kairomones are semiochemicals involved in interspecific interactions of insects that benefit the receiver to the detriment of the emitter. One of these interactions is host searching by parasitoids which detect these compounds as a strategy to locate their hosts. In the case of the larval ectoparasitoid, Habrobracon hebetor Say (Hymenoptera: Braconidae), the \'frass\' of Anagasta kuehniella Zeller (Lepidoptera: Pyralidae) releases a kairomone that attracts females parasitoids. Considering that A. kuehniella has been used for egg production in order to keep natural enemy rearing, this kairomone is undesirable, because it may lead to high H. hebetor infestation and causes important losses during the rearing process. One of the attempts to control these infestations could be the use semiochemical-baited traps. However, as the kairomone is still unidentified, the aim of this work was to isolate it - the first step for its identification. The kairomone was extracted by solvent washing and aeration of A. kuehniella \'frass\'. Then the extracts were tested in a four-way olfactometer with female parasitoids, registering the time taken in each treatment. The active washing extract was fractionated in five fractions in a silica column, and its attractivity was evaluated to proceed to isolation. The extracts and fractions were then analysed by gas chromatography with flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS), in order to locate exclusive compounds in active samples. Furthermore, the fractions from the washed extract were aerated to extract their volatile compounds that were also analysed by GC-MS. The kairomone was isolated in the 75% ether fraction, indicating that it is a polar compound. Comparing the chromatograms, only one peak on the HP-5ms column was selected as belonging to the kairomone. On the Rtx-1ms column, the peak bifurcated, indicating that at least one of the compounds is part of the kairomone. The methodological combinations of this work provided the isolation of the kairomone present in A. kuehniella \'frass\' and the selection of at least one compound that comprises the semiochemical that attracts H. hebetor parasitoid, resulting in the first source of information about its chemical structure for its future identification.
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46

Scott, Gary Terri. "The role of micro-organisms in the production of semiochemicals in the interdigital secretion of the bontebok, Damaliscus pygargus pygargus." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/53774.

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Thesis (MSc)--Stellenbosch University, 2004.
ENGLISH ABSTRACT: Bontebok, Damaliscus pygargus pygargus, formerly classified as D. dorcas dorcas, are territorial animals with interdigital glands between the toes of the forelegs. Males regularly defecate on dung heaps, on which they often lie, to communicate with other members of their species. They also communicate by means of visual displays, scent marking and occasionally with scraping or pawing of dung heaps. It is assumed that scent marking with the interdigital secretion serves to define territories frequented by these antelope. These glands secrete a complex mixture of volatile and non-volatile compounds and the volatile compounds in the secretion serve as a chemical signal for other bontebok. It has been suggested that the interdigital secretion is not produced in its final composition by the interdigital gland alone, but that microbial activity is responsible for many of the compounds present in the secretion. In general, many compounds can be attributed to the by-products of microbial hydrolysis of triglycerides, a common characteristic of sebum. It is well documented that micro-organisms inhabit the deep recesses of sebaceous glands and the presence of micro-organisms has been found to be consistent in all antelope exocrine glandular areas. This study involved the chemical characterisation of the volatile metabolites produced in vitro by micro-organisms from the interdigital cavity of the bontebok. Various comparative studies were made, one of which was comparison of the metabolites produced by the individual microbial species as well as the total community of bacteria incubated in different media. A comparison of the compounds identified in the interdigital secretion and the metabolites produced by the micro-organisms in the different media was also made. The volatile metabolite extracts of the individual bacterial species and of the total community were chemically characterised by low-resolution gas chromatography-mass spectroscopy. Classes of compounds identified from the volatile metabolite extracts include: • Acids - Aliphatic (saturated and unsaturated) • Alcohols - Aliphatic (saturated and unsaturated) • Aldehydes - Aliphatic (saturated and unsaturated) • Aromatic compounds • Ketones - Aliphatic (saturated and unsaturated) • Pyrazines • Dimethyldisulphide • Squalene and cholesterol Several qualitative differences were found between the compounds identified in the volatile metabolite extracts of the micro-organisms when incubated in tryptic soy broth (TSB) and minimal salt medium (MSM). In particular, when the microbes were incubated in TSB medium a number of pyrazines were found that were not present when utilising MSM as a medium. Additional qualitative differences were found between the compounds identified in the metabolite extracts of the individual bacterial species and the total community of bacteria, when incubated in both TSB and MSM media. A comparison of the interdigital secretion and the metabolite extracts of the microbial communities incubated in TSB and MSM revealed that many compounds produced in MSM corresponded to the compounds identified in the interdigital secretion. These corresponding compounds were found to be saturated and unsaturated acids, aldehydes and squalene. Furthermore, there was only one corresponding compound in the case of TSB as medium.
AFRIKAANSE OPSOMMING: Die bontebok, Damaliscus pygargus pygargus, voorheen geklassifiseer as D. dorcas dorcas, is 'n territoriale dier met interdigitale kliere tussen die kloutjies van die voorpote. Ramme ontlas gereeld op mishope, waarop hulle dikwels lê, om met ander lede van die spesie te kommunikeer. Hulle kommunikeer ook deur middel van visuele seine, reukmerking en soms deur mishope met die voorpote te kap of te skraap. Reukmerking met die interdigitale afskeiding dien klaarblyklik om gebiede wat deur hierdie diere bewoon word, af te baken. Die interdigitale kliere skei 'n komplekse mengsel van vlugtige en nie-vlugtige verbindings af en die vlugtige verbindings dien as chemiese sein vir ander bontebokke. Die vermoede bestaan dat die interdigitale klier nie alleen verantwoordelik is vir die finale samestelling van die interdigitale afskeiding nie, maar dat mikrobiese aktiwiteit bydra tot die produksie van baie van die verbindings wat in die afskeiding aanwesig is. Sekere verbindings kan in die algemeen toegeskryf word aan die vorming van die neweprodukte van mikrobiese hidrolise van trigliseriede, 'n algemene eienskap van sebum. Dit is bekend dat die diep holtes van vetkliere 'n goeie teelaarde is vir mikroorganismes en daar is gevind dat mikroorganismes feitlik deurgaans voorkom in alle anteloop eksokriene klierareas. Hierdie studie behels die chemiese karakterisering van die vlugtige metaboliete wat in vitro deur mikroorganismes van die interdigitale klierholte van die bontebok geproduseer word. Verskeie vergelykende studies is uitgevoer waarvan een die vergelyking was van die metaboliete wat deur die individuele mikrobiese spesies sowel as die totale gemeenskap van bakterieë geproduseer word tydens inkubasie in verskillende media. Vergelyking van die verbindings wat in die interdigitale afskeiding geïdentifiseer is met die metaboliete wat in verskillende media geproduseer is, het ook deel van die studie uitgemaak. Die vlugtige metaboliet ekstrakte van die individuele bakteriese spesies en van die totale gemeenskap is chemies gekarakteriseer deur middel van laeresolusie gaschromatografie-massaspektrometrie. Die volgende groepe verbindings is onder andere in die vlugtige metaboliet ekstrakte geïdentifiseer: • Sure - Alifaties (versadig en onversadig) • Alkohole - Alifaties (versadig en onversadig) • Aldehiede - Alifaties (versadig en onversadig) • Aromatiese verbindings • Ketone - Alifaties (versadig en onversadig) • Pirasiene • Dimetieldisulfied • Skwaleen en cholesterol Verskeie kwalitatiewe verskille is gevind tussen die verbindings wat geïdentifiseer is in die vlugtige metaboliet ekstrakte van die mikroorganismes onderskeidelik in TSB medium en MSM geïnkubeer. Opvallend was byvoorbeeld die voorkoms van pirasiene in gevalle waar mikroorganismes in TSB medium geïnkubeer is, terwyl hierdie groep verbindings afwesig was wanneer MSM gebruik is. Onderlinge kwalitatiewe verskille is ook gevind tussen die verbindings wat geïdentifiseer is in die metaboliet ekstrakte van die individuele bakteriese spesies en die totale gemeenskap van bakterieë, wanneer in TSB medium sowel as in MSM geïnkubeer is. Vergelyking van die verbindings in die interdigitale afskeiding en in die metaboliet ekstrakte van die mikrobiese gemeenskappe, het getoon dat 'n aantal verbindings wat in MSM geproduseer is, ooreenstem met verbindings wat in die interdigitale afskeiding geïdentifiseer is. Daar is gevind dat hierdie verbindings versadigde en onversadigde sure en aldehiede en skwaleen is. Met TSB as medium was daar slegs een ooreenstemmende verbinding.
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47

Silva, Weliton Dias da. "Comportamento sexual da broca-do-café, Hypothenemus hampei (Ferrari, 1867) (Coleoptera: Curculionidae: Scolytinae)." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-17032010-141611/.

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O estudo do comportamento sexual dos insetos abrange todos os eventos ocorridos desde a formação dos casais por meio do cortejo, até a separação dos mesmos após a cópula. Esses estudos são importantes e representam o primeiro passo em pesquisas que visam à elucidação de feromônios da espécie alvo. No caso da broca-do-café, Hypothenemus hampei (Ferrari), que é considerada mundialmente a principal praga do café, existe uma lacuna de informações sobre o comportamento sexual dessa espécie. Além disso, as pesquisas têm sido direcionadas para o uso de armadilhas contendo alcoóis (ex: etanol e metanol) visando o manejo dessa praga, mas com resultados conflitantes. Em razão disso, o objetivo do presente trabalho foi estudar o comportamento sexual de H. hampei, como suporte para estudos subseqüentes visando a elucidação do feromônio da espécie. As cópulas de H. hampei ocorreram em qualquer horário dentro de um ciclo de 24 horas. Embora em menor freqüência, 60% dos casais realizaram pelo menos uma cópula na idade de 0-24 horas, chegando a 100% dos casais nas demais idades. A maior atividade sexual foi observada nas idades de 48-72 e 72-96 horas, onde, nessa última, ocorreram 6,9 ± 0,47 cópulas por casal com duração de 2,04 ± 0,13 minutos cada. Os padrões comportamentais exibidos foram semelhantes a outros grupos de curculionídeos, com pré-cópula, cópula e pós-cópula. Os resultados indicaram ainda a presença de um feromônio produzido pelos machos mediando o acasalamento. A possibilidade de as fêmeas de H. hampei realizarem a recópula após sua saída dos frutos abre novas perspectivas sobre a viabilidade deste feromônio no manejo desta praga.
The sexual behavior study in insects includes all the events occurred since of pair encounter by means of courtship until their separation after mating. These studies are important and represent the first step of researches that aim to elucidate pheromones of target species. Regarding the coffee berry borer, Hypothenemus hampei (Ferrari), which is the most important coffee pest around the world, little is known about its sexual behavior. Furthermore, the researchers have been focused on the use of traps based on alcohols (e.g. ethanol and methanol) with aims of managing this pest, but its results are conflicting. For that reason, the aim of the present work was to study the sexual behavior of H. hampei, whose it will give support to subsequent studies about evaluation of pheromone this species. Daily mating rhythm of H. hampei occurred on any time of 24- hour cycle. Although at low rates, 60% of paired adults mated at least once when they were 0-24 hours, reaching 100% in older pairs. The highest sexual activity was observed in the ages of 48-72 and 72-96 hours, being in this last one the occurrence of 6,9 ± 0,47 matings/pair with a mean duration of 2,04 ± 0,13 minutes each. The pattern behavior displayed was similar to other groups of Curculionidae, with premating, mating and postmating. The results also indicated the presence of a pheromone produced by the males that mediates mating. The possibility of the H. hampei females recopulates after they leave the fruits opens new perspectives to investigate the viability of using this pheromone in management of this pest.
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48

Peck, Gavin Earl. "Potential Semiochemicals of Wheat (Triticum aestivum L.) Induced by Oviposition and Feeding of the Wheat Stem Sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae)." Thesis, Montana State University, 2004. http://etd.lib.montana.edu/etd/2004/peck/PeckG1204.pdf.

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Cephus cinctus Norton (Hymenoptera: Cephidae), the wheat stem sawfly, is currently the most devastating insect pest of wheat production in Montana. Currently, no effective controls are in place to check its damage and spread throughout wheat fields in the northern Great Plains. Natural biological control of sawflies occurs primarily in the form of larval parasitoids which attack the sawfly larva in the stem; however, these parasitoids are not reliably effective in controlling sawfly populations. Insect damage induces chemical changes in plants, and often these changes are part of a defensive response to the insect injury. Some of these chemical changes are apparent in the volatile chemicals produced by the plants and may include semiochemicals used by sawflies and parasitoids. Identifying the changes in volatile production could enhance the understanding of sawfly-wheat plant-parasitoid interactions and lead to more effective control measures for the wheat stem sawfly. I investigated the differences in the volatile chemicals produced by sawfly-infested and uninfested wheat plants and endeavored to determine if those differences were qualitative or quantitative. Additionally, I wanted to determine if changes in volatile production induced by the wheat stem sawfly could be mimicked by wounding coupled with the application of sawfly cuticular wax to wheat stems or by the injection of frass-treated water into the internodes of wheat stems. Volatiles of infested and uninfested wheat plants were collected and compared, with the results indicating that sawfly damage induces quantitative changes in some volatile chemicals produced by wheat. These results are discussed regarding their context within sawfly-wheat plant-parasitoid interactions and implications for better sawfly control. Volatiles from sawfly-infested, uninfested, frass-water-injected, and pin-pricked/waxtreated plants were also collected, and differences in 11 compounds selected from the results of the 1st experiment were compared. The results of this experiment found that pin-pricked/wax-treated plants came closer to mimicking the volatile production changes induced by sawfly infestation, but neither frass-water injection nor pin-pricked/cuticular wax application reliably induced the same changes in wheat volatiles that sawfly infestation did. There was, however, a definite response of the wheat to the application of the sawfly cuticular wax, and its significance is discussed.
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49

Page, Jennifer Lynn. "The effects of plume property variation on odor plume navigation in turbulent boundary layer flows." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29752.

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Thesis (Ph.D)--Biology, Georgia Institute of Technology, 2009.
Committee Chair: Weissburg, Marc; Committee Member: Hay, Mark; Committee Member: Kubanek, Julia; Committee Member: Webster, Donald; Committee Member: Yen, Jeannette. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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50

Meurisse, Nicolas. "Chemical ecology of rhizophagus grandis (Coleoptera: Monotomidae) and its application to the biological control of dendroctonus micans (Coleoptera: Scolytinae)." Doctoral thesis, Universite Libre de Bruxelles, 2008. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210567.

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The Eurasian spruce bark beetle Dendroctonus micans is a major pest of spruce which is expanding its range in France, Turkey, England and Wales. Its monospecific predator Rhizophagus grandis has followed naturally the bark beetle into most areas and, since the 1960s, has also been mass-produced and successfully released within newly infested locations.

In this scope, the development of an effective trapping method would be very useful to assess the bark-beetle presence at previously uninfested sites, or predator establishment after release or natural spread. We demonstrated the efficiency of oxygenated monoterpenes-baited kairomone traps to monitor R. grandis in various epidemiological conditions, including areas localized behind or at the limit of the pest’s distribution, or in areas where artificial releases were performed. Because the predator is strictly species-specific, another exciting possibility offered by the kairomone trapping is the indirect monitoring of the pest itself in areas of unknown status (e.g. areas under colonization, or considered as at risk at medium- term).

R. grandis is also considered as one of the most valuable natural enemies to strike aggressive North-American Dendroctonus species. In this respect, R. grandis has been recently applied in a neo-classical biological program against the red turpentine beetle D. valens, which invaded China from North America in the late 1990’s. In laboratory tests conducted on pine logs in the laboratory, or on living pine trees in the field, we demonstrated that R. grandis adults can successfully enter and reproduce into D. valens galleries.

In Europe, R. grandis is the only species regularly found in the brood systems of D. micans, where adults and larvae attack the gregarious larvae of their prey. In such enclosed systems, R. grandis’ functional response is therefore influenced by various interrelated components, such as the prey density, the predator density, or the prey distribution. Measuring the predator’s success in terms of larval survival and growth rates, we demonstrated the time spent by R. grandis larvae to wound and kill their prey to be the main factor limiting their development. This factor may be considerably influenced by the proportions of diseased, wounded or molting prey rise in the brood system, for instance as a result of an increase in prey density, or due to the presence of conspecific adults (which wound their prey but do not consume them entirely). Furthermore, our tests suggest that no cannibalism or noticeable intraspecific competition occurred between R. grandis larvae, whereas some lighter mode of competition probably took place.

R. grandis also exhibits a reproductive numerical response to prey density, which mainly relies on the perception of chemical stimuli and inhibitors released in the bark beetle brood system. In the current study, we developed a non-destructive approach to follow the dynamics of volatile compound production, using sequential sample collection on SPME fibers. Our tests demonstrated that the larval activity of D. micans or D. valens strongly influences the release of some oxygenated monoterpenes. However, our attempts to correlate the relative quantities of some identified chemicals to offspring production were less successful as it concerns the identification of potential oviposition stimuli and inhibitors.

The problematic rose by the progression of D. micans, as well as detailed results of each of the described above studies are discussed in the two published papers and the three manuscripts forming this thesis. Bringing all these studies together, several perspectives are also presented in the general discussion.

/

Ravageur des épicéas, Dendroctonus micans est toujours en voie d’extension en France, en Turquie, en Angleterre et au Pays de Galles. Dans la plupart de ces zones, le dendroctone est accompagné de manière naturelle par son prédateur monospécifique, Rhizophagus grandis. Depuis les années 1960, le prédateur a également fait l’objet d’une production de masse et de programmes de lâchers dans les zones d’arrivée récente du scolyte.

Dans le cadre de la lutte biologique contre D. micans, les gestionnaires forestiers doivent donc estimer au plus tôt la présence du ravageur dans des zones jusque là indemnes, mais également vérifier l’établissement du prédateur par progression naturelle ou résultant d’introductions délibérées. Dans la présente étude, nous avons démontré l’efficacité de pièges d’interception appatés à l’aide de monoterpènes oxygénés pour la capture de R. grandis. Celle-ci s’est faite dans différentes conditions épidémiologiques, incluant notamment des zones situées en arrière du front de progression du scolyte et des zones où des lâchers artificiels ont été réalisés. Comme R. grandis est strictement inféodé au dendroctone, un autre avantage de la technique est la possibilité de réaliser un dépistage indirect du ravageur dans les zones où son statut est incertain (zones en cours de colonisation, ou considérées comme à risque à moyen terme).

Par ailleurs, R. grandis est également considéré comme un des meilleurs ennemis naturels potentiels pour lutter contre d’autres espèces de Dendroctonus aggressifs. Dans cette optique, R. grandis a été récemment utilisé dans un programme de lute biologique contre D. valens, ravageur invasif arrivé en Chine dans la fin des années 1990 en provenance d’Amérique du Nord. Nous avons démontré la capacité de R. grandis à s’introduire et à se reproduire dans les galeries de D. valens lors de tests de laboratoire, mais aussi sur des arbres vivants en pinèdes.

En Europe, R. grandis est strictement inféodé aux galeries de D. micans, où larves et adultes du prédateur s’attaquent aux larves grégaires du scolyte. Dans ce système clos, la réponse fonctionelle de R. grandis est influencée par plusieurs facteurs étroitement corrélés, la densité de proies, la densité de prédateurs, et la distribution des proies. En mesurant l’efficacité de prédation de R. grandis en termes de survie des larves et de taux de croissance, nous avons démontré l’influence sur leur développement du temps passé par les larves à blesser et à tuer leurs proies. Ce facteur est par ailleurs fortement dépendant de la proportion de larves malades, blessées ou en cours de mue au sein du système ;une proportion qui peut augmenter en réponse à une augmentation de la densité de proies, ou lorsque des adultes sont présents (ceux-ci blessent les proies mais ne les consomment pas entièrement). Enfin, nos tests suggèrent qu’il n’existe que peu de cannibalisme ou de compétition intraspécifique entre larves de R. grandis, tandis que des modes de compétition moins importants prennent vraisemblablement place.

R. grandis présente également une réponse numérique reproductive à la densité de proies disponibles, principalement basée sur la perception de stimuli et d’inhibiteurs présents dans les galeries du scolyte. Par la collecte de composés volatils présents dans ces systèmes à l’aide de fibres SPME, nous avons développé une méthode non-destructive pour suivre la dynamique de production des médiateurs chimiques. Nos tests ont démontré que l’activité des larves de D. micans ou D. valens influence fortement la dynamique de production de certains monoterpènes oxygénés. En revanche, il n’a pas été été possible de corréler les différents composés identifiés au nombre de larves de R. grandis présentes dans le système.

La problématique soulevée par la progression de D. micans, de même que les résultats détaillés de chacune des études décrites ci-dessus sont discutés dans les deux papiers publiés et les trois manuscrits formant cette thèse. Les différentes perspectives apportées par ce travail sont également présentées dans la discussion générale.


Doctorat en Sciences agronomiques et ingénierie biologique
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