Lethal and sublethal effects of five insecticides on the demography of a parasitoid wasp

Habrobracon hebetor Say (Synonym: Bracon hebetor) is an important ectoparasitoid wasp of lepidopteran pests. In this research, the effects of chemical and botanical insecticides including fenvalerate, propargite, buprofezin, dayabon and palizin were investigated on this biocontrol agent. The contact exposure bioassays showed that LC50 values under insecticides treatment were 0.52, 47.44, 23.30, 31.35 and 62.47 mg a.i./L, respectively. Then, the young female wasps of H. hebetor (<24 h old) were exposed to LC30 of selected insecticides for 24 h and their demography was investigated. The sublethal results showed that adult longevity, survival, fecundity, fertility, hatch rate and sex ratio of H. hebetor negatively were affected by the tested insecticides. Finally, the intrinsic rate of increase (rm) was obtained after treatment and was 0.27 day−1 for the control versus 0.14, 0.18, 0.21, 0.19 and 0.24 day−1 for the insecticides, respectively. The effects of dayabon and palizin have not been evaluated yet on moth pests and must be investigated in the future. Our results show that palizin has the lowest negative effects on the demography of H. hebetor and therefore is a compatible insecticide for integrated pest management programs.