In 1989, a modified AcNPV was released in Geneva, New York. The virus AcNPV, genetically engineered for reduced persistence compared to wild type, was released on a 0.8-hectare, open field plot of cabbage. Experimental releases of genetically modified virus for the control of gypsy moth were conducted in 1993. In each case risk assessment evaluations were made prior to the field releases and research permits were granted based on the low potential for adverse environmental consequences. Public concern over the level of pesticide use in food production has fostered the development of alternative, non-chemical methods of insect control.
Microbial pesticides utilize insect pathogens as a means of reducing insect populations.
Pathogens include various species of fungi, nematodes, and bacteria. The best known example of a microbial pest control product is the bacterium, Bacillus thuringiensis or Bt. Bt is commercially available and recommended for the control of a number of agricultural and forest pests. Viruses comprise another important class of insect pathogens. The potential for biological control by insect viruses, known as baculoviruses, has been studied for several years.