A Novel Delivery Method for Ant (Hymenoptera: Formicidae) Toxicants

Described here is a new delivery method for ant toxicants consisting of an inert carrier, an attractant, and a toxicant. Unlike baits, this system does not contain a food source, but uses ant to ant contact rather than trophallaxis as the mechanism for horizontal dispersal of the toxicant through the colony. We evaluated six potential attractants and found that only triolein increased treated filter paper removal by the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae). On corn cob grits, removal was optimized at a rate of 60 μl triolein/g grits. In laboratory assays, mortality of fire ants offered corn cob grits treated with a combination of fipronil and triolein was 90.5%, versus 46.5% when grits were treated with the same rate of fipronil without triolein. In both lab and field trials, the removal of grits treated with a combination of fipronil and triolein was greater than removal of controls but less than removal of grits treated with triolein alone.