FACTORS DETERMINING THE EFFECTIVENESS OF LYSEPHLEBUS TESTACEIPES AS A BIOLOGICAL CONTROL AGENT OF CEREAL APHIDS
Wheat, Peanut and Other Field Crops Research
2012 Annual Report
1a.Objectives (from AD-416):
The objective of the proposed research is to develop new knowledge on the ecology and biology of biological control agents of cereal aphids.
1b.Approach (from AD-416):
We will assess the effectiveness of key biological control agents in traditional and emerging small grain crop production systems and elucidate the intra- and extra-field processes that influence their population dynamics. More specifically, we will: (1) elucidate the effect of landscape factors on the population dynamics of the key greenbug parasitoid, Lysephlebus testaceipes; and (2) elucidate the effect of co-occurring cereal aphids on parasitism of greenbug by Lysephlebus testaceipes.
During FY 2012 we conducted a field experiment in which we measured parasitism rates in 8 production winter wheat fields in north central Oklahoma. We measured parasitism of aphids by Lysephlebus testaceipes in wheat field edges approximately one week prior to wheat planting in each field, and then measured parasitism again in the wheat field edges and the field itself approximately one week after wheat had germinated in the field. We quantified landscape structure for each of the fields and determined grass species richness and abundance in the field edge. The research progresses towards understanding and quantifying the effect of extra-field processes at multiple spatial scales on parasitism by L. testaceipes on cereal aphids in wheat fields.