Evaluation of sublethal effects of tetraniliprole, flupyradifurone, flubendiamide, and spirotetramat insecticides on biological parameters of the ectoparasitoid wasp Habrobracon hebetor Say (Hymenoptera: Braconidae).

Abstract

The parasitoid wasp Habrobracon hebetor Say (Hymenoptera: Braconidae) is one of the important parasitoids used for the biological control of larval stages of moths such as Pyralidae and Noctuidae, which include major agricultural, orchard, and stored product pests. This wasp species is widely utilised in biological control programmes targeting these economically significant lepidopteran pests. In this study, the sublethal effects of four insecticides (tetranelypyrole, flupyradifurone, flubendiamide, and spirotetramat) on the biological parameters of the parasitoid wasp H. hebetor were investigated using demographic toxicology methods. The parasitoid wasp was reared on larvae VI of the Mediterranean flour moth in a growth chamber (27 ± 2°C, 65 ± 5% RH, and a photoperiod of 16:8 (light:dark) hours). The estimated LC₂₅ values from the bioassay experiments on the adult stage of the wasp were used. The estimated LC₂₅ values were 30.8, 130.8, 807, and 34.2 µg ai/L for tetraniliprole, flupyradifurone, flubendiamide, and spirotetramat pesticides, respectively. The results showed that the net reproductive rates (R₀) due to treatment by tetraniliprole, flupyradifurone, flubendiamide, spirotetramat, and control were 50.25, 50.66, 64.72, 57.49, and 71.33 females per generation, respectively. The intrinsic rate of population increase (r_m) was 0.226, 0.240, 0.242, 0.238, and 0.259 females/female/generation for tetraniliprole, flupyradifurone, flubendiamide, spirotetramat, and control, respectively. The population parameters calculated included the age-stage age-specific survival rate (l_x) and age-specific fecundity of the total population (m_x). The demographic toxicology analysis showed that tetraniliprole had the highest toxicity, while flubendiamide had the lowest toxicity to adult wasps. In case of conducting additional field tests and confirming the laboratory results, it can be concluded that the insecticides flupyradifurone and flubendaimide may be suitable options for integrated pest management programs.