Epiphyas postvittana is the principal insect
pest of vineyards and is responsible for significant annual losses to the
Australian wine industry.
Currently, control of this pest is attempted through a combination of ‘soft’
insecticides, mating disruption, habitat manipulation and biological control by
egg parasitoid wasps of the genus Trichogramma. Unfortunately, each of
these methods has drawbacks and limitations, and control can therefore be
patchy and unreliable. Spiders are ubiquitous in agroecosystems, however their
specific role in biocontrol remains unclear.Research indicates that spiders are important predators of lepidopteran
and hymenopteran eggs, larvae and adults and thus within a vineyard ecosystem,
they have the potential to either augment or disrupt the biocontrol of E.
postvittana by Trichogramma wasps.
My project is designed to produce
results that will inform grower’s management practices, specifically in terms
of reducing chemical input through more effective biocontrol options. The
overall aim of my study is to clarify the role of spiders in vineyards with
regard to the biocontrol of E. postvittana. Initially, I am developing a
PCR-based gut content analysis protocol to identify spiders that are preying on
E. postvittana and/or their Trichogramma spp. parasitoids.Once
the important predatory species have been identified, I will investigate the
predator-prey dynamic in laboratory based behavioural assays and feeding
trials.Finally, I will be conducting
manipulative field experiments to validate my findings and test redictions
arising from my results.