Molecular tracking of life-stage dependent intraguild predation

Intraguild interactions are influenced by the density of predators present in an ecosystem. In holometabolous organisms, larvae are vulnerable to predation and represent an alternative food source. Both lady beetles and lacewings are biological control agents of aphids, one of the most detrimental pest insects in crop production systems. Therefore, these taxa potentially overlap in their use of prey and at times may compete or exhibit intraguild predation. The goal of this project is to examine the frequency of intraguild predation of the green lacewing [Family: Chrysopidae] and lady beetle species Coccinella septempunctata, Coleomegilla maculata, and Hippodamia convergens and compare levels of intraguild predation to that of spiders, another dominant predator group in many agroecosystems.  To estimate predator population numbers, five suction samples were collected at random locations in each of four buckwheat fields every three weeks. The cover crop buckwheat (Fagopyrum esculentum) was selected because it is known to harbor natural enemies.  Preliminary analysis of the suction samples indicates that abundances differed between predator groups and that their populations fluctuate over time. Assays of lacewing, lady beetle, and spider specimens collected by hand directly following suction samples will be applied to evaluate levels of intraguild predation. Analyses will determine the complexity of interactions between numerically dominant predator taxa and potential influence on aphid suppression. Our results hold value for the agricultural community by providing knowledge of predator interactions occurring in cover crops prior to establishment of production crop.