ABSTRACT
Research to develop improved methods of managing serious insect pests of delta crops, specifcially cotton, by use of natural insect pathogens was begun in 1987 at the USDA, ARS, Southern Insect Management Laboratory (SIML) at Stoneville, MS. Previous research had shown that non-crop hosts, particularly early-season weeds, act as hosts for the tobacco budworm, Heliothis virescens (F.), and cotton bollworm, Helicoverpa zea (Boddie), prior to the presence of crop hosts. It was theorized that tobacco budworm and cotton bollworm populations could be managed by either controlling the insects on the weeds using insecticides, or by controlling the early season hosts themselves via herbicides or mowing. Since insect pathogens (microbial insecticides) are considered to be among the safest methods of insect control, research was begun to investigate their use in a management scheme. Positive results of small field and cage tests led to large area studies, beginning with a 64,000-acre test in 1990, and culminating in 215,000-acre tests in 1994 and 1995. Results of tests to date indicate that virus application could be accomplished at a reasonable cost, and that such treatment consistently reduced the number of moths emerging from weed hosts by > 70%. Herein, we present brief results of the long-term study that led to the present question of what the future holds for this project.
|