EFFECTS OF PLANT IDENTITY AND CHEMICAL-CONSTITUENTS ON THE EFFICACY OF A BACULOVIRUS AGAINST HELIOTHIS-VIRESCENS

Baculoviruses are arthropod-specific, dsDNA viruses primarily used to control lepidopteran pests. A limitation of the use of baculoviruses f or pest control is that their efficacy is modifiable by host-plant che micals. The levels of phenolic substrates and two foliar oxidative enz ymes, peroxidase (POD) and polyphenol oxidase (PTO), were significant predictors of disease caused by a baculovirus in Heliothis virescens f ed on either cotton or lettuce; POD was the more influential of the tw o enzymes. The higher the plant phenolase activity, the lower the perc ent mortality and the slower the insects died from viral infection. Wh ether a particular class of phenolic substrates was correlated with en hanced or attenuated baculoviral disease depended upon context, i.e., admixture. Diminution of viral efficacy by plant oxidative activity ma y compromise the compatibility of baculoviruses with other components of an integrated pest management system such as host plant resistance.