TRI-n-Butyltin Fluoride as a Controlled-Release Mosquito Larvicide

Abstract

Trialkyltin compounds have long been recognized as antifouling agents and molluscicides,¹ and more recently have demonstrated potential as mosquito larvicides.² Bis-n-tributyltin oxide (TBTO) and tributyltin fluoride (TBTF) are the most commonly used compounds and have been monolithically incorporated in a series of controlled-release formulations.^{3 4} Both organotin compounds are non-persistent in the biosphere, degrading through a series of daughter compounds to non-toxic stannic oxide. TBTF has a half life of 6.7 days⁵ and TBTO has a half life of 15.4 days in water.⁶ They are probably noncarcinogenic and nonmutagenic, both effects being absent in short-term studies. Teratogenicity is not evident in four successive mouse generations.⁸ Field studies of formulations containing TBTO and TBTF in elastomers have demonstrated long-term snail control under environmentally adverse conditions.^9,10 Both materials are fairly specific toxicants for fresh-water snails, mosquito larvae, and certain fly larvae.