Modified maximum dose bioassay for assessing insecticide response in field populations of Bemisia tabaci (Hemiptera: Aleyrodidae)

Authors: PERIER, JERMAINE - University Of Georgia; CREMONEZ, PAULO - University Of Georgia; PARKINS, ALBERTA - University Of Georgia; KHEIRODIN, ARASH - University Of Georgia; Simmons, Alvin; RILEY, DAVID - University Of Georgia

Submitted to: Journal of Entomological Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/18/2024
Publication Date: 4/19/2024
Citation: Perier, J.D., Cremonez, P.S., Parkins, A.J., Kheirodin, A., Simmons, A.M., Riley, D.G. 2024. Modified maximum dose bioassay for assessing insecticide response in field populations of Bemisia tabaci (Hemiptera: Aleyrodidae). Journal of Entomological Science. 59(4). https://doi.org/10.18474/JES23-88.
DOI: https://doi.org/10.18474/JES23-88

Interpretive Summary: The sweetpotato whitefly continues to be a major pest of vegetable and other crops. There is a need to know as early as possible if whiteflies in crops are resistant to insecticides that may be used to try to control them. A quick (within 24-h) assay revealed that among six commonly used insecticides for whitefly control, this pest had developed elevated resistance to some of the insecticides, while Cyantraniliprole killed the most whiteflies at both low and high dose rates. The use of this method and information will help the agricultural community in prioritizing insecticides for use or rotation in an insecticide resistance management program.

Technical Abstract: Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) MEAM1 continues to be a major pest of vegetable cultivation. Field-by-field surveying is an effective approach to determining the susceptibility status of a pest population to an insecticide. During 2020-2022, a modified maximum dose bioassay method was employed for a field survey of whitefly populations in Tift County, GA, to characterize the insecticide response of several commonly used insecticides for whitefly control. The results of the evaluations were produced in 24-h following a 24-h root drench period. This rapid bioassay allows for field evaluations before spray applications to reduce the adult life stage of the species. From the survey, the novel neonicotinoids, dinotefuran, and flupyradifurone were the most effective insecticides from the IRAC group (4a). Cyantraniliprole was the most effective insecticide overall, with 88% and 86% mortality following exposure at the maximum and low dose, respectively. Conversely, control with another diamide, cyclaniliprole, was poor. Adding a low dose to the maximum dose provided an early indication of poor control with a product potentially signaling an increase in resistance. Specifically, a significant difference between the maximum and low doses suggests that the dose-response curve had shifted toward resistance development in a field population. The proposed bioassay method is meant for systemic insecticides that offer quick responses on adults and nymphs. The use of this method will improve evaluations prioritizing insecticides for use or rotation in an insecticide resistance management program.