Effectiveness of brassica seed meals as potential ecofriendly larvicides for mosquito control

Authors: Weiler, Lina; Hay, William; Behle, Robert; McCormick, Susan; Vaughn, Steven; Berhow, Mark; MUTURI, EPHANTUS - Centers For Disease Control And Prevention (CDC) - United States

Submitted to: Entomological Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 8/11/2022
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The efficacy using different concentrations of five defatted brassica seed meals [Brassica juncea (Pacific Gold), Lepidium sativum (Garden cress), Sinapsis alba (Ida Gold), Thlaspi arvense (Pennycress), and Thlaspi arvense - heat treated] and two major chemical constituents (allyl isothiocyanate and benzyl isothiocyanate) were evaluated for toxicity to Aedes aegypti larvae. Bioassays were used to determine the lethal concentration for 50% (LC50) mortality of larvae exposed to seed meal treatments in water after 24- and 72-h exposures. All seed meals except the heat treated T. arvense were toxic to mosquito larvae. L. sativum seed meal had the fastest activity and was the most toxic treatment to larvae (LC50 = 0.04 g/120 mL dH2O at the 24 h exposure). At the 72-h evaluation, the LC50 values for B. juncea, S. alba and T. arvense were 0.05, 0.085 and 0.09 g/120mL dH2O, respectively. The T. arvense (heat treated) seed meal was ineffective to the larvae. Benzyl isothiocyanate being more toxic to larvae 24h post treatment (LC50 = 5.2 ppm) compared with allyl isothiocyanate (LC50 = 19.8 ppm). This is the first report evaluating the efficacy of five brassica seed meals and their major chemical constituent against mosquito larvae. The results of this study open new opportunities by demonstrating that defatted seed meals, the byproduct of seed oil extraction, can serve as a promising ecofriendly larvicide to control mosquitoes.