PERSISTENCE OF STEINERNEMA-CARPOCAPSAE AND S-GLASERI (RHABDITIDA, STEINERNEMATIDAE) AS MEASURED BY THEIR CONTROL OF BLACK CUTWORM (LEPIDOPTERA, NOCTUIDAE) LARVAE IN BENTGRASS

A field study was done to evaluate persistence of the entomopathogenic nematodes Steinernema carpocapsae (Weiser) and S. glaseri (Steiner) in controlling black cutworm, Agrotis ipsilon (Hufnagel), Iarvae in creeping bentgrass, Agrostis palustris Hudson. Bentgrass plots were baited with black cutworms on several dates following nematode application. Mortality of black cutworms in plots treated with nematodes was significantly greater than in untreated plots at 1 d after treatment. S. carpocapsae provided a slightly higher level of black cutworm control than S. glaseri. Persistence of nematodes was lost 8 d after nematode application in the field. Laboratory bioassays with black cutworm and greater wax moth, Galleria mellonella (L.), larvae using soil cores extracted from field plots confirmed field results. The nematode's ability to recycle in an insect cadaver and reinfest a newly introduced insect host was not observed in this study.