Red Imported Fire Ant Workers (Hymenoptera: Formicidae) Protect Their Queens from Steinernema carpocapsae All (Nematoda: Steinernernatidae)

摘要

The susceptibility of red imported fire ant workers and queens accompanied by workers to the entomopathogenic nematode Steinernema carpocapsae All was evaluated in the laboratory. The infective juveniles (IJs) of S. carpocapsae All at the dose of 3.49x10~4 were able to infect the queen accompanied both by 6 workers and by about 100 workers, the mortalities of infected queens (MOIQs) accompanied by 6 workers were 83.33% after 3 days, 90.00% after 6 and 9 days, respectively, but the MOIQs accompanied by 100 workers were 33.33% after 3 days, 36.67% after 6 days, and 40.00% after 9 days, respectively. The MOIQs accompanied by 6 workers were significantly higher than those accompanied by 100 workers after the same days. However, the MOIQs were increased,but are not significantly different with increased treatment time (3,6 and 9 days). It was observed that the nematodes in the dishes which the queens survived after 9 days also survived and showed infectivity to waxmoth larvae Galleria mellonella. Theseresults show that the workers are not susceptible to the nematodes and can protect their queens from the nematodes.