I am investigating the impact of spiders on an established biocontrol system within vineyards.  Epiphyas postvittana, the Light Brown Apple Moth, is an indigenous leaf-rolling moth, which has become the principal insect pest of grapevines and other horticultural crops.  Initial control of this pest was carried out through heavy spray programmes of insecticides including DDT and lead arsenate, however this practice often lead to outbreaks, resistance and unacceptable levels of chemical residues on the fruit.  Currently control of the Light Brown Apple Moth is achieved through a combination of ‘softer’ insecticide application, mating disruption through the use of pheromone traps, habitat manipulation, and biological control.  A host of native parasitoids are known to parasitise the egg and larval stages of E. postvittana, the most common and diverse of which, are the hymenopteran egg parasitoids of the genus Trichogramma (Westwood) (Hymenoptera: Trichogrammatidae).  Research indicates that spiders are important predators of both lepidopteran and hymenopteran larvae and eggs, and thus have the potential to augment, or to disrupt, the system of biocontrol between Trichogramma spp. and E. postvittana.  Using a PCR based approach to gut content analysis, I will identify the spider species preying on the moths and/or wasps.  Following this, I will explore the predator-prey dynamic with laboratory based behavioural assays.  I will then be able to test my findings and predictions through manipulative field experiments.  My project is designed to generate results that will be useful to growers in terms of their pest management strategies, particularly in reducing the necessary insecticide input