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) i n controlling black cutworm, Agrotis ipsilon (Hufnagel), Iarvae in cre eping bentgrass, Agrostis palustris Hudson. Bentgrass plots were baite d with black cutworms on several dates following nematode application. Mortality of black cutworms in plots treated with nematodes was signi ficantly greater than in untreated plots at 1 d after treatment. S. ca rpocapsae provided a slightly higher level of black cutworm control th an S. glaseri. Persistence of nematodes was lost 8 d after nematode ap plication in the field. Laboratory bioassays with black cutworm and gr eater wax moth, Galleria mellonella (L.), larvae using soil cores extr acted from field plots confirmed field results. The nematode's ability to recycle in an insect cadaver and reinfest a newly introduced insec t host was not observed in this study.