Evaluation of Insecticides as Baits for Imported Fire Ants in Laboratory Sreening Tests, 1979

Insecticides that show promise in preliminary screening tests by causing delayed toxicity are further tested against entire laboratory colonies of imported fire ants. The chemicals are formulated in a bait and fed to colonies that have been starved for 5 days just prior to the test. The toxic bait (5 g/colony) is placed in a tray containing the colony for 24-96 h after which it is replaced with the standard laboratory diet. Observations on colony activity and mortality are recorded weekly. The test is continued until the queen, brood (larvae and pupae) and an estimated 90% or more of the workers are dead or the colony recovers and returns to normal.