Side-effects of azadirakhtin (NeemAzal) and flubendiamide (Takumi) on functional response of Habrobracon hebetor (Hymenoptera: Braconidae)

Habrobracon hebetor say (hymenoptera: braconidae) is one of the major parasitoids which is used against various lepidopteran larvae in iran. due to extensive application of chemical pesticides in farms, study of their side effects on natural enemies is necessary. therefore, in this study, side-effects of two prevalent insecticides, neemazal and takumi (at dosage 2000 mg/l and 437.5mg/l, respectively), on functional response of h. hebetor to different densities of 5^th instar larvae of ephestia kuehniella zeller (lepidoptera: pyralidae) were evaluated in laboratory conditions. host densities of 2, 4, 8, 16, 32 and 64 were randomly exposed to selected treated females of h. hebetor in 8 cm petri dishes. ten replications were conducted for each host density. the control was treated with water. the data were analyzed using logistic regression to find functional response type and non-linear regression to estimate functional response parameters. the results revealed a type ιι response for all treatments. this study showed that h. hebetor had the shortest (0.269 h) and longest (1.822 h) handling times in takumi and neemazal treatments, respectively. also, the highest and lowest searching efficiency of h. hebetorwere recorded for the takumi (0.188 h^–1) and neemazal (0.0396 h^–1) treatments, respectively. according to the results of the study, takumi may be more compatible with biological control agent in ipm programs.