Field Tests with the Nuclear Polyhedrosis Virus for Control of Heliothis spp. in the Southern High Plains of Texas, 19641

Field-plot tests were conducted in the southern High Plains with various dosages of the nuclear polyhedrosis Virus for control of Heliothis spp. in cotton. In general, better control was obtained with increase in virus dosage. At the rate of 100 larval equivalents per acre per application (1 LE = 6X109polyhedral inclusion bodies), the seed yield with the virus was equivalent to that secured with chemical insecticide mixtures. The predominant species in these tests was the bollworm, Heliothis zea (Boddie). The tobacco budworm, H. virescens (F.), was not present in economic numbers. The results of these tests indicate that the nuclear polyhedrosis virus was effective in reducing the bollworm populations and increasing yields.