Surface spray applications of non-repellent insecticides disinfest balled and burlapped nursery stock of red imported fire ants

To contain the spread of imported fire ants in the United States, there is a Federal Imported Fire Ant Quarantine that restricts the transport of articles that can harbor fire ants beyond established infested areas. To improve methods to disinfest fire ants from regulated articles such as balled-and-burlapped (B&B) nursery stock, the efficacy to disinfest red imported fire ants, Solenopsis Invicta, from B&B root balls with insecticides not repellent to fire ants was determined. Out of the four non-repellent insecticides tested, surface sprays of dinotefuran and indoxacarb resulted in >99% reduction in worker ants and only small amounts (≤2 ml) of brood being recovered. In each of the dinotefuran and indoxacarb treatments, 0 and 1 root balls out of 4, were considered infested, respectively. The dinotefuran treatments applied at ½ and full label rates were also able to prevent root ball infestations from migrating colonies of S. Invicta for at least 4 months. The non-repellent insecticide treatments are hypothesized to allow more contact with insecticide treated soil via ant digging and tunneling behavior, than that of repellent insecticides. Surface sprays of non-repellent insecticides may be an efficient, imported fire ant quarantine treatment for B&B nursery stock.