Intraguild Predation Among Coccinellidae and Lysiphlebus Testaceipes in an Oklahoma Winter Wheat System

Lysiphlebus testaceipes Cresson mitochondrial DNA within the gut of the ladybeetle Hippodamia convergens Gurin-Mneville was detectable with PCR following intraguild predation of the parasitized greenbug Schizaphis graminum Rondani. Detection was possible up to 16h post-feeding 100% of the time using Ltesta F & R primers. Three fields of winter wheat were sampled on 24 February, 10 March, and 24 March (2006) for intraguild predation of L. testaceipes by coccinellids; proportion of intraguild predation events of this nature ranged from 0.667 to 0.871. Both 3rd and 4th instar H. convergens larvae were fed 4mg/day of greenbugs in 3 different stages of parasitism by L. testaceipes to determine the suitability of that stage as a food source. Results showed reduced survivability for both 3rd and 4th instar H. convergens larvae when feeding on greenbugs in all stages of parasitism by L. testaceipes with chronic effects having greater negative impacts.Department of Entomology and Plant Patholog