RECOMBINANT VIRAL INSECTICIDES - DELIVERY OF ENVIRONMENTALLY SAFE ANDCOST-EFFECTIVE PRODUCTS

Biological control agents such as baculovirus insecticides have many a ttributes which make them attractive alternatives to synthetic chemica l pesticides. However, there have been several economic and agronomic barriers to their widespread use. Among the obstacles to commercializa tion of viral insecticides have been high production costs, the lack o f efficacious formulation and application technologies, and a slow spe ed of action. Biotechnology has contributed several advances toward ov ercoming these obstacles. The high cost of in vivo production can be r educed significantly using a newly developed high-density rearing syst em termed HeRD. The HeRD technology can be used to rear many different species of lepidopterous larvae for production of viral insecticides, as hosts for parasitoid production, or for sterile-male release progr ams. Using this technology, the baculovirus production costs are equiv alent to sprayable Bt toxins. The field efficacy of viral pesticides a nd other biological control agents requires cost effective, biological ly based formulation and application technologies. Based on current fi eld efficacy evaluations of baculovirus pesticides, formulation/applic ation technologies must be improved for viral pesticides to compete ef fectively and consistently in most pesticide markets. Through recombin ant DNA technology, it is now possible to insert foreign pesticidal ge nes into viral pesticides, resulting in faster time to death or, more importantly, time to cessation of feeding of the target pests. However , the commercial use of recombinant pesticides has raised several pote ntial environmental issues, including possible effects on non-target o rganisms, ecological interactions, mitigation and genetic stability. G enetic strategies have been developed to mitigate most of the potentia l problems associated with recombinant baculovirus pesticides. Five fi eld tests have been conducted in the U.S. to evaluate these strategies . The laboratory and field results illustrate that the genetic strateg ies employed ensure environmental safety while also reducing productio n costs.