Biology and biological control potential of bethylid wasps
Khidr, Sahand Kamal (2012) Biology and biological control potential of bethylid wasps. PhD thesis, University of Nottingham.
This thesis presents a series of experiments on the evolutionary ecology of the reproduction, behaviour, chemical and molecular characteristics of bethylid wasps in the genus Goniozus. Part One investigates host quality by varying host age after paralysis. The quality of paralyzed hosts declines with time since paralysis negatively influences life-history characteristics of Goniozus nephantidis. Assessment of host metabolomic profiles show which chemicals change as hosts age. Part Two investigates the effect of kin recognition on contest behaviour among adult females ofGoniozus legneri. Competitive behaviour was thus used to study the basis of kin recognition mechanisms. Wasps that are genetic kin and wasps that are reared on the same host behave less aggressively towards each other than do non-kin and nonhostmates. It is likely that cuticular hydrocarbon profiles are used by wasps in kin recognition. The environmental and genetic influences on wasp cuticular hydrocarbon profiles were explored: chemical composition differed according to both wasp species and host species. Part Three investigates genetic characteristics of Goniozus legneri populations on kin recognition behaviour. A molecular genetic marker system was developed for Goniozus species. Microsatellites showed clear polymorphism in six primer pairs and are likely to be a valuable tool in the future for closely related species. One of these markers was utilized to assess sex allocation at oviposition, thus avoiding potentially biasing influences of developmental mortality. Developmental mortality does not differ between the sexes but mortality increased, sex ratio variance across offspring groups and can obscure relationships between sexual composition andg roup size that are present at oviposition. A tendency for Goniozus legneri to lay male and female eggs in spatial separation was also observed. Although the focus of these studies is on fundamental aspects of bethylid biology, advances in all of these areas have potential to enhance the deployment of these parasitoids in biological pest control.
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