Suitability of Schizaphis graminum parasitized by Lysiphlebus testaceipes as intraguild prey for Chrysoperla rufilabris

Authors: JESSIE, CASI - Oregon State University; GILES, KRISTOPHER - Oklahoma State University; ROYER, TOM - Oklahoma State University; PAYTON, MARK - Oklahoma State University; Elliott, Norman - Norm; JESSIE, WILLIAM - Oregon State University

Submitted to: Southwestern Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/14/2019
Publication Date: 3/1/2019
Citation: Jessie, C.N., Giles, K.L., Royer, T.A., Payton, M.E., Elliott, N.C., Jessie, W.P. 2019. Suitability of Schizaphis graminum parasitized by Lysiphlebus testaceipes as intraguild prey for Chrysoperla rufilabris. Southwestern Entomologist. 44(1):21-33. https://doi.org/10.3958/059.044.0103.
DOI: https://doi.org/10.3958/059.044.0103

Interpretive Summary: In the Southern Great Plains, winter wheat is often the predominant agricultural crop. The greenbug is a sporadic aphid pest wheat in this region and capable of widespread destruction during outbreaks. Natural enemies, such as parasitoid wasps, lady beetles, and green lacewings are also common in wheat fields and have been shown to regularly prevent aphid outbreaks. Previous studies have demonstrated that lady beetles readily feed on parasitized aphids, which has negative consequences for their survival and ability to control greenbug outbreaks. Green lacewings often outnumber lady beetle's wheat fields but the effects of potentially eating parasitized aphids by green lacewings has not been studied. We tested the feeding capabilities of green lacewing larvae (the life stage that feeds on aphids) and conducted a diet suitability study to determine if green lacewing larvae are capable of feeding, surviving, and developing on parasitized greenbugs. We found that larvae readily feed on parasitized greenbugs. The importance of the results of this study lie in understanding those factors which reduce, or increase, the potential of natural enemies to control aphid pests of wheat. The results suggest that the impact of lacewings on biological control of aphids in wheat is reduced when parasitism levels are high.

Technical Abstract: In the Southern Great Plains, winter wheat (Triticum aestivum L.) is often the predominant crop in agricultural landscapes. The greenbug (Schizaphis graminum Rodani) is a sporadic aphid pest on small grains in this region and capable of widespread destruction during outbreaks. Natural enemies, such as parasitoid wasps, lady beetles, and green lacewings are also common in wheat fields and have been shown to regularly prevent aphid outbreaks. When natural enemies co-exist, and compete for common resources, intraguild predation (IGP) is likely to occur. Previous studies have demonstrated that lady beetles readily feed on parasitized aphids but IGP has negative consequences for survival, development, and adult body size. Green lacewings, especially Chrysoperla spp., significantly outnumber lady beetles in Oklahoma winter cropping systems but the effects of IGP of parasitized aphids by green lacewings has not been studied. We tested the feeding capabilities of first and third instar C. rufilabris and conducted a diet suitability study to determine if green lacewing larvae are capable of feeding, surviving, and developing on mummified greenbugs. We found that C. rufilabris first and third instars readily feed on mummified greenbugs.