[Truncated] The ecological and evolutionary aspects of resource use in phytophagous insects have been well studied over the years, yet relatively few studies have investigated host-use variation displayed by parasitoid insects. This study combined a range of quantitative and molecular genetic techniques in association with behavioral and life-history bioassays to investigate host-range divergence in Diaeretiella rapae (M'Intosh) (Braconidae: Hymenoptera) a generalist parasitoid of aphid insects.Using quantitative genetic techniques, characters associated with the parasitoid's primary host, Brevicoryne brassicae (L.) were found to be unlinked to utilization of non crucifer hosts. Characters of oviposition preference were subsequently investigated in simple Petri dish bioassays to identify the relative importance of different environmental cues utilized during the host selection process on which evolutionary mechanisms may act. The experimental evidence presented supports the view that both physical and chemical factors play an important role in the oviposition behavior of D. rapae, turning on a behavioral sequence of events that can lead to oviposition.
|Qualification||Doctor of Philosophy|
|Publication status||Unpublished - 2002|