Steinernematid nematode drenches for control of fire ants, Solenopsis invicta, in Florida

We selected a strain of Steinernema feltiae produced by Biosys Inc. (Palo Alto, CA) for field evaluation after screening several strains of Steinernema and Heterorhabditis spp. in the laboratory. After 96 h, the strain we selected had produced queen mortalities of 40% and 58% in 5,000 and 50,000 nematode dosaged, respectively. Mortality of workers and brood, although not quantitatively determined, was estimated to be at least 80%. Mortality of queens, workers or brood was not observed in the control group. In separate tests we observed that colonies of ants vacated soil treated with high concentrations of nematodes.