Session: What Have We Learned: A Conversation on 15 Years of Spinosad Use in Public Health Symposium
121 - Efficacy and nontarget effects of a spinosad-based larvicide in Minnesota vernal pools and cattail marshes
Tuesday, March 5, 2024
5:15pm – 5:25pm
Location: D3
Abstract: Larvicides that contain spinosad are used to control mosquitoes in diverse aquatic habitats. These same habitats are home to other invertebrates, including Crustacea and mollusks. A double-blind study evaluated the effects of Natular G on spring Aedes spp. and nontarget invertebrates in vernal wetlands. Within 14 d after application, Natular G controlled spring Aedes larvae by 53-84%, depending on species, but had no significant effects on fairy shrimp, fingernail clams, or freshwater snails. A second double-blind study evaluated effects on Coquillettidia perturbans and nontarget isopods and amphipods in cattail marshes. Treatment reduced emergence of Cq. perturbans by 25% but did not change the number of isopods or amphipods. The two studies indicate Natular G could be effective against spring Aedes in vernal wetlands, less so against Cq. perturbans in cattail marshes, and yet pose minimal risk to crustaceans and mollusks in either vernal wetlands or cattail marshes.
