Location: Imported Fire Ant and Household Insects Research
Project Number: 6036-10400-001-010-T
Project Type: Trust Fund Cooperative Agreement
Start Date: Feb 1, 2024
End Date: Feb 1, 2026
Objective:
To determine if the the judicious use of insecticides that are not repellent to fire ants can result in the rapid elimination of fire ant colonies. The fast elimination of fire ant colonies is needed in areas frequented by the public because the aggressive stinging behavior of fire ants pose a public health hazard. Current fire ant bait treatments typically take over a week to eliminate colonies, and insecticides that kill ants on contact, often allow fire ants colonies to move and recover. This research addresses a gap in the integrated pest management of fire ants.
Approach:
Year 1. Testing will initially be conducted in Florida to determine the speed of action of the non-repellent insecticides containing dinotefuran, indoxacarb, and perhaps other active ingredients. Testing will be conducted on field colonies and insecticides will be applied by hand-held sprayer with the insecticide volume applied adjusted to wet (but not saturate) the fire ant nest surface. Colonies will be evaluated daily for a minimum of 5 days based on activity ratings (to minimize nest disturbance) and colony death confirmed by excavating nests when no fire ant activity is observed on 2 consecutive days or on the 14th day after treatment. Colony movement will also be monitored. Study will follow a randomized complete block design with blocking based on colony size, with 5 – 10 nests per treatment. Percent reductions in fire ant population index ratings will be compared among treatments by two-way analysis of variance and appropriate multiple comparison test. The number and percentages of dead colonies and time to inactivity will also be reported. Pending consistency of results, a second field test will be conducted with the most promising insecticide treatment(s) to increase replications.
Year 2. Non-repellent insecticides that demonstrate strong efficacy of rapidly (e.g, <5 days) eliminating colonies in Florida will be field tested in the desert conditions of the Coachella Valley of California. A randomized complete block design will be followed, similar to what was outlined in the year 1 study. However, the fire ant activity at the nest and fire ant counts at food lures placed adjacent to treated nests will be made to assess colony survivorship. (Population index ratings are unreliable indicators of colony status in desert climates). Nests in treated sites will be monitored daily for 1 week. A two-way analysis of variance and a multiple comparison test will compare final ant lure counts among treatments. The number and percentages of dead colonies and time to inactivity will also be reported per treatment.
