As we know that the red imported fire ants (Solenopsis invicta Buren) are most notorious and difficult to control. These ants are considered as a major agricultural and urban pest and they can be medically and environmentally harmful. Red imported fire ants generally invade home lawns, school yards, athletic fields, golf courses and parks. Natural enemies including microsporidian protozoan (Thelohania solenopsae) the fungus (Beauveria bassiana), South African parasitoid flies (Pseudacteon tricuspis and Pseudacteon curvatus) and entomopathogenic nematodes have a potential to use as a biological control agents to kill red imported fire ants. Recently, it has been reported that the infective juveniles of two entomopathogenic nematode species including Steinernema carpocapsae All and S. scapterisci can infect the queens of the red imported fire ant, Solenopsis invicta under laboratory conditions. Both nematodes can cause up to 100% mortality of fire ant queens 9 days after their exposure. For correct dosages of nematodes and their efficacy, please read the paper listed below.
Zhang, L.K., Zhang, P.B., Cao, L. and Han, R.C. 2010. Susceptibility of red imported fire ant queens to the entomopathogenic nematodes Steinernema carpocapsae All and S. scapterisci. Sociobiology. 55: 519-526.