OVIPOSITION OF BLACK CUTWORM (LEPIDOPTERA, NOCTUIDAE) ON CREEPING BENTGRASS PUTTING GREENS AND REMOVAL OF EGGS BY MOWING

Oviposition and egg location of black cutworm, Agrotis ipsilon (Hufnag el), removal of eggs by mowing, and survival of eggs on grass clipping s were evaluated on a creeping bentgrass, Agrostis palustris Hudson, g olf putting green. Caged moths laid similar numbers of eggs on bentgra ss maintained at cutting heights of 3.2, 4.8, or 13.0 mm. Nearly all e ggs were laid singly on the tips of grass blades. In 3 trials, mowing of plots 48 h after oviposition removed an estimated 75-91% of the egg s at the 3.2-mm cutting height, and 81-84% at the 4.8-mm cutting heigh t. In another test, 97% of marked eggs on grass blades were recovered on clippings in the mowing basket. Five to 10% of the eggs were dislod ged from grass blades by the mower roller. Survival of eggs on grass c lippings harvested with the greens mower was as high as 90% in the lab oratory and 50% in the field. This study suggests that daily mowing re moves most black cutworm eggs from golf putting greens, implying that larger cutworms found on greens may originate from surrounding, high-m owed turf. Disposal of clippings away from greens may be important for reducing reinfestations by crawling larvae.