Natural mortality of leaffooted bug (Hemiptera : Heteroptera : Coreidae)eggs in cowpea

摘要

Predation and parasitism of eggs of Leptoglossus phyllopus (L.) were monitored from 1993 to 1997 by placing egg masses on cowpea [Vigna unguiculata (L.) Walp.] and other wild and cultivated, host plants. Hymenopteran parasitoids reared from eggs were Gryon carinatifrons (Ashmead), Gryon pennsylvanicum (Ashmead) (Scelionidae), Anastatus spp. (Eupelmidae), and an unidentified encyrtid. Scelionids comprised 93% of parasitoids, with a 4:1 ratio of G. carinatifrons: G. pennsylvanicum. Parasitoids were able to develop in coreid eggs that had been stored at <-20 degrees C. Data from 1995 and 1996 showed that intensity of egg parasitism varied among host plants and was significantly lower on corn compared with cowpea and wild Asteraceae, reaching a maximum of 61.9% on late-season cowpea. Egg predation was high on all host plants tested, ranging from 28.8% on blueberry, Vaccinium corymbosum L., to 72.2% on the wild host Pyrrhopappus carolinianus (Walter) DC.