Laboratory Studies with Nine Amidinohydrazones, a Promising New Class of Bait Toxicants for Control of Red Imported Fire Ants12

Abstract

AC 217,300 (Tetrahydro-5,5-dimethyl-2(IH)-pyrimidinone,[3-[4-trifluoromethyl)phenyl]-1-[2-[4-(trifluoromethyl)phenyl]ethenyl]-2-propenylidene]hydrazone) was the most effective of nine amidinohydrazones tested as bait toxicants against workers Solenopsis invicta Buren. In screening tests, this chemical dissolved in soybean oil (SBO) showed delayed action over more than a 10-fold dosage range. In secondary tests, this toxicant formulated in granular SBO baits at concentrations of 2.5–10% (in SBO) and fed to entire laboratory colonies (queen, immatures, and 10,000–100,000 workers) either killed the entire colony or killed most of the workers and the colony queen.