Evaluating the mosquitocidal potential of the isoxazoline sarolaner against the yellow fever mosquito, Aedes aegypti (Diptera: Culicidae)

Authors: DAGG, KENDRA - University Of Florida; Estep Iii, Alden; BURGESS, EDWIN - University Of Florida

Submitted to: Medical and Veterinary Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/25/2025
Publication Date: 7/14/2025
Citation: Dagg, K.A., Estep III, A.S., Burgess, E.R. 2025. Evaluating the mosquitocidal potential of the isoxazoline sarolaner against the yellow fever mosquito, Aedes aegypti (Diptera: Culicidae). Medical and Veterinary Entomology. 1-10. https://doi.org/10.1111/mve.12827.
DOI: https://doi.org/10.1111/mve.12827

Interpretive Summary: Aedes aegypti is the primary vector of several pathogens of public health significance. Insecticide-based preventative measures are a key component of vector-borne disease control programs. However, widespread insecticide resistance threatens the effectiveness of current control strategies. This study evaluates the insecticidal efficacy of sarolaner against both laboratory-susceptible and insecticide resistant strains of Ae. aegypti through various exposure routes. Efficacy varied based on the type of exposure but generally efficacy of sarolaner was comparable or better than existing commercially available standards. This study highlights sarolaner's potential as an effective adulticide and larvicide against Ae. aegypti, supporting its further evaluation as a candidate for new chemical formulations.

Technical Abstract: Aedes aegypti is the primary vector of several pathogens of public health significance. Insecticide-based preventative measures are a key component of vector-borne disease control programs. However, widespread insecticide resistance threatens the effectiveness of current control strategies. Sarolaner, an isoxazoline insecticide, offers a novel mode of action and is primarily used for controlling ticks, fleas, and mites in companion animals. This study evaluates the insecticidal efficacy of sarolaner against both laboratory-susceptible and resistant strains of Ae. aegypti through various exposure routes. In topical assays, sarolaner outperformed permethrin by >8-fold and >21-fold higher efficacy against resistant strains at 24 and 72 hr, respectively. Conversely, it underperformed in susceptible strains by over 8-fold and 2-fold at the same time points. In larval assays, sarolaner exhibited >300-fold greater toxicity than spinosad at 24 and 48 hr for both susceptible and resistant strains. Blood-feeding assays showed sarolaner was more toxic than ivermectin by over 17-fold and 10-fold in susceptible and resistant strains, respectively, up to 120 hr. While sarolaner was less toxic than dinotefuran in resistant strains through sugar feeding, it was over 3-fold more toxic in susceptible strains. Notably, no cross-resistance was detected with dinotefuran or ivermectin through oral, sugar, or blood-feeding applications, though slight cross-resistance was observed with permethrin and spinosad. This study highlights sarolaner's potential as an effective adulticide and larvicide against Ae. aegypti, supporting its further evaluation as a candidate for new chemical formulations.