Determining Field Insecticide Efficacy on Whiteflies with Maximum Dose Bioassays

• Published in: Insects (Basel, Switzerland) Vol. 14; no. 6; p. 510
• Main Authors: Cremonez, Paulo S G, Perier, Jermaine D, Simmons, Alvin M, Riley, David G
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01-06-2023; MDPI
• Subjects: Agricultural research; Aleyrodidae; Bemisia tabaci; Bioassays; Biological assay; Chemical properties; Control; Cotton; Crop damage; Crops; Damage; Effectiveness; Farmers; Field tests; Generalized linear models; Hypotheses; Imidacloprid; Insecticide resistance; insecticide resistance management (IRM); Insecticides; Laboratories; Loam soils; maximum-dose bioassay; Pest control; Pests; Physiological aspects; Population biology; Population dynamics; Potatoes; Pyriproxyfen; Survival; Sweet potatoes; sweetpotato whitefly; United States; United States > US; sweetpotato whitefly; maximum-dose bioassay; insecticide resistance management (IRM); Bemisia tabaci
• ISSN: 2075-4450; 2075-4450
• DOI: 10.3390/insects14060510

We conducted a rapid bioassay method to assess insecticide efficacy for controlling adult sweetpotato whitefly
in squash and cucumber crops before insecticide applications. The study aimed to evaluate the accuracy of a 24-hour laboratory bioassay in determining maximum dose insecticide efficacy in the field. Ten insecticides were evaluated using leaf-dip bioassays, and their effectiveness was tested across eight cucurbit field experiments in Georgia, USA, during the 2021 and 2022 field seasons. The maximum dose, defined as the highest labeled rate of an insecticide diluted in the equivalent of 935 L ha
of water, was used for all bioassays. Adult survival observed in the bioassay was compared to adult field count-based survival 24 h after treatment. A low concentration (1/10 rate) was used for imidacloprid, flupyradifurone, pyriproxyfen, and cyantraniliprole to assess insecticide tolerance in the whitefly population. Overall, significant positive correlation between laboratory bioassay and field efficacy was reported, explaining 50-91% of the observed variation. The addition of the low dosage was helpful, indicating that no rate response was consistent with susceptibility to the tested insecticide, while a rate response was associated with a loss of susceptibility between 2021 and 2022.