INFECTIVITY OF STEINERNEMA-CARPOCAPSAE (RHABDITIDA, STEINERNEMATIDAE)IN STERILIZED AND HERBICIDE-TREATED SOIL

The infectivity of the entomopathogenic nematode, Steinernema carpocap sae (Weiser), against larvae of the greater wax moth, Galleria mellone lla (L.), was investigated in sterile, nonsterile, and glyphosate-trea ted soil cores from a stand of bentgrass, Agrostis palustris Hudson. S oil cores were sterilized by high-pressure steam or methyl bromide fum igation. Another set of soil cores was treated with the herbicide, gly phosate. Nematode infectivity was significantly greater in sterile soi l than in nonsterile and glyphosate-treated soil on days 3 and 8 after nematode application. No significant differences were detected by day 15 after nematode treatment. Results suggest the presence of a biotic factor(s) that limits the persistence of insect control provided by e ntomopathogenic nematodes in bentgrass.