Efficacy of the Entomopathogenic Nematode #355
on Red Imported Fire Ant, Solenopsis invicta, Infesting Turfgrass

Clyde S. Gorsuch and Randy E. McWhorter
Department of Entomology

Objectives

Most red imported fire ant (RIFA), Solinopsis invicta, control measures employ the use of traditional insecticides. There is interest in developing biological controls for management of RIFA on commercial turfgrass. This test was designed to test the efficacy of the entomopathogenic nematode #355, Steinernema riobravis, against RIFA.

Methods and Materials

The trial was conducted on the Edisto Beach Golf Club, Edisto Island, SC. Plots were selected on 11 October and treated between 1830 and 2030 hours. Because of heavy dew, the Award was not put out on 11 October. There was light rain the morning of 12 October which increased to a steady rain by noon. A total of 0.8 inches of rain fell on 12 October. No Award was put out because of wet conditions.

An evaluation was planned on 30 October, but our truck broke down during the trip and we never made it to Edisto Island. The plots were checked on 9 November. The weather was cold with temperatures in the mid 30's during the night. There was very little activity in the mounds when they were disturbed.

A final trip to the course was made on 11 and 12 December. Again the weather was very cold with frost on the greens the morning of 12 December. Because of the lack of activity, no effort was made to rate the plots.

Results and Discussion

The data are presented in Table 1. It is difficult to say whether there was any reduction of RIFA activity in the nematode treated plots. Ideally, the treatments should have been applied earlier in the year. However, due to a lack of a suitable site with irrigation on the infested areas, the treatments were delayed until October.

Acknowledgments

We would like to acknowledge the support of Dr. Randy W. Martin, biosys Inc., for his support. We are grateful to Mr. Eugene Scarborough Jr., Superintendent, Edisto Beach Golf Club for his cooperation and excellent care of the test areas.