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Evaluation of early-season baculovirus treatment for suppression of Heliothis virescens and Helicouverpa zea (Lepidoptera: Noctuidae) over a wide area

Informally Refereed

Abstract

Pheromone trap counts of F1 male cotton bollworm, Helicoverpa zea (Bodie), and tobacco budworm, Heliothis virescens (F1) were used to assess the effect of areawide suppression achieved by early-season application of a Heliocoverpa/Heliothis specific nuclear polyhedrosis virus. Eggs (F2) were collected from cotton and other hosts to characterize the surviving reproductive populations. Trap and egg collection sites were established at 1.6-km intervals (n = 5) in four cardinal directions from the center of control and treated plots (259 km2 = 10 by 10 mi). Traps also were placed at five additional intervals in four cardinal directions beyond the treated plot to assess the effect of dispersal. The effect of treatment was demonstrated by deviations in trap capture patters within a year betweem treated and control plots and between years in the treated plot. Rates of increase between generations were calculated from the number of moths captured in one generation divided by the number from the previous generation. The rate of increase for the first field generation of H. virescens in the treated plot (1990) was 13% compared with 38% in the control plot (1990) and 38% in the treated plot in the year before treatment (1989). The rate of increased for the first field generation of H. zea was 36% in the treated plot (1990) compared with 55% in the control plot (1990) and 95% in the treated plot the year before treatment (1989). Rates of increase for both species in the subsequent generation remained low in the treated plot (1990) compared with the control plot (1990) and with the previous year (1989). Our results indicate that a single virus application can reduce the adult H. virescerns and H. zea populations emerging from alternative hosts present early in the season. Other methods for improving the efficacy of treatments were discussed.

Keywords

Heliothis/Helicoverpa, baclovirus, area-wide evaluation

Citation

Hayes, Jane Leslie; Bell, Marion. 1994. Evaluation of early-season baculovirus treatment for suppression of Heliothis virescens and Helicouverpa zea (Lepidoptera: Noctuidae) over a wide area. Journal of Economic Entomology, Vol. 87(1): 58-66
https://www.fs.usda.gov/research/treesearch/28098