Winter Ecology of the Parasitoid Lysiphlebus Testaceipes Cresson

Abstract

The purpose of this study was to investigate cold weather ecology of the greenbug parasitoid, Lysiphlebus testaceipes Cresson (Hymentoptera: Aphidiidae). These investigations included (1) determination of the supercooling point for L. testaceipes and its greenbug host, Schizaphis graminum (Rondani)(Homoptera: Aphididae); (2) determination of the 12 hour lethal low temperature (LTemp50) for L. testaceipes mummies and adults; (3) determination of the lethal time (LTime50) at just below the developmental threshold for L. testaceipes mummies and adults(5C), and at the 12 hour LTemp50 (-6C); (4) an investigation of the 24 hour functional response of L. testaceipes on greenbug at 2, 4, 6, 8, 10, 12, and 14C; (5) an investigation of parasitoid activity in the field using greenbug infested sentinel plants to detect oviposition by L. testaceipes and other parasitoids during the 2003-2004 winter wheat growing season in Payne county, Oklahoma.