RETRACTED ARTICLE: Residual effect of two chemical insecticides on functional response of Habrobracon hebetor say (Hymenoptera: Braconidae) to Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)

Abstract

Braconid wasps are among the most successful parasitoids of lepidopteran pests worldwide. The sublethal effects of two chemical insecticides, lufenuron (Match®) and thiacloprid + deltamethrin (Proteus®), were studied on functional response of Habrobracon hebetor Say to Ephestia kuehniella Zeller larvae. Seven host densities (2, 4, 8, 16, 32, 64 and 96) were used during a 24 h period under controlled conditions of 27 ± 1 °C, 70 ± 5% R.H. and 16:8 h (L:D). The resulting data were appropriately fit to Type II functional response models in all treatments, including: (1) control (a = 0.0967 h−1; and Th = 0.2128 h); (2) lufenuron (a = 0.0950 h−1 and Th = 0.2162 h) and (3) thiacloprid + deltamethrin (a = 0.0806 h−1 and Th = 0.3431 h). The maximum theoretical parasitism rate (T/Th) was 112.78 estimated for control wasps. There was no significant difference between the values of attack rates (a and a + Da) in all treatments, while the handling time was statistically affected in female wasps treated with thiacloprid + deltamethrin. These findings will be useful to the safe deployment of lufenuron in pest management programs.