Transgenerational effect of insecticides on juvenile development time of the Sweetpotato whitefly parasitoid Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae)

Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae) is a highly efficient parasitoid that has been commercially used for augmentative biological control of the sweetpotato whitefly Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae). The success of control efforts with this parasitoid could be compromised by the use of non-selective pesticides. This study was conducted to determine if acetamiprid, imidacloprid, thiamethoxam, spinetoram, and sulfoxaflor had transgenerational effects on juvenile development of E. mundus. The mean development time from oviposition (OVP) to first sign of parasitism (FSP) for progeny of females treated with control was 9.03 days, which was the shortest compared to the insecticide treatments. After FSP, the control groups reached their pre-pupal (PP) stage in an average time of 3.85 days, while it was in the range of 3.98-4.46 days for insecticide-treated groups. The developmental period from pre-pupal to black-eyed pupal stage ranged from 2.32-2.69 days for parasitoids treated with insecticides, but it was 2.22 days for the control group. The overall mean development time-from oviposition until adult emergence-was 16.24 days for control, which was statistically shorter than all other treatments. Spinerotam and sulfoxaflor prolonged immature development by 2.37 and 1.83 days, respectively, when compared with the control. Male development was slightly shorter than that of female in control, spinetoram, and sulfoxaflor groups, and the opposite was true for the neonicotinoids. Compared to the neonicotinoids, the non-neonicotinoids had more negative effect on juvenile development of E. mundus.