P27 - Toxicity of three commonly used mosquito larvicides on Procambarus alleni

Wednesday, March 25, 2026

12:15 PM - 1:45 PM PDT

Location: Hall A

Presenter(s)

Timothy D. McNamara, PhD (he/him/his)

Postdoctoral Researcher
University of Florida, Florida, United States

Co-Author(s)

EM

Estelle M. Martin, Ph.D.

Assistant Professor
University of Florida, Florida, United States
CB

Cason Bartz, n/a

Director
City of Gainesville Mosquito Control, Florida, United States

Abstract: Florida is home to a wide diversity of crayfish, which serve as critical components of the ecosystems which they inhabit. Many of these species are important to humans as sources of food, pets, and as part of the recreational fishing industry. Additionally, several species of crayfish in the state are listed as either threatened or endangered, making their conservation within the state of foremost importance. However, there is evidence that some mosquito larvicidal compounds may negatively impact decapods or other crustaceans. To date, no research has directly examined the risks of mosquito abatement larvicide applications to crayfish. We are in the process of conducting toxicity assays using (S)-Methoprene-, Bacillus thuringiensis var. israelensis-, and Spinosad-based larvicide products on the widely distributed and ecologically important Everglades crayfish (Procambarus alleni) to determine the dosage-response relationship, No Observable Adverse Effect Concentration (NOAEC), and Lowest Observable Adverse Effect Concentration (LOAEC). We will also be conducting environmental exposure surveillance of waterways in Gainesville, FL where these products are applied to measure the exposure rate and persistence of products in the environments crayfish inhabit. These data will aid mosquito control professionals in making application decisions in environments where P. alleni and other closely related crayfish species are prevalent.