Bottom up effect on top down control: Do plant provided resources improve lepidopteran pest management in Virginia collards?

Understanding how buckwheat (Fagopyrum esculentum Moench) companion plantings impact natural enemy abundance, and pest suppression in adjacent crops, may provide alternative control methods thereby slowing the rate of insect resistance to pesticides and reducing pesticide exposure to the applicator and surrounding habitats. Buckwheat has been widely used as a companion planting on vegetable farms, vineyards, and orchards to supply nectar and pollen and encourage arthropod natural enemy populations. However, scientific data demonstrating the true biological control benefit of such companion plantings are scarce. The primary objective of this project was to determine the impact of buckwheat companion planting on lepidopteran pest abundance, parasitoids abundance, parasitism, and the predator and parasitoid communities in collards. In 2012, overall abundance of pest caterpillars did not vary with distance and imported cabbageworm (Pieris rapae L.) was the most abundant species. Parasitism of imported cabbageworm larvae did not differ with distance from available nectar sources. Abundance of parasitoids was not significantly different with distance, and the average rate of parasitism was 50%. Data for 2013 are currently being collected.