ABSTRACT
Demand for effective, more selective, safer pesticides, consistent with sustainable agriculture continues to push the search for newer systems as well as modifying the existing ones. Insects are subject to diseases caused by viruses, bacteria, fungi, protozoans and nematodes. Many members of these groups have been evaluated as biocontrol agents. Most pathogens and nematodes tend to infect primarily insect larvae and are only effective against this stage. Although bacterial control agents of Bacillus thuringiensis family are currently the leading bioinsecticides, viral and fungal agents are gradually making headway. For example, baculoviruses directly compete with Bl for the control of lepidopterous insects, albeit feebly at present. With the advances in development of recombinant baculoviruses, that are more virulent and fast acting, baculoviruses have a great potential for effective integration into pest management system
The baculoviruses are the naturally occurring invertebrate-specific pathogens that infect some important lepidopteran (butterflies and moths) hymenopteran
(forest pests) insects. Their high pathogenicity, narrow host range and complete safety to vertebrates and plants, make them ideal candidates for biological control of these insects. The viral pesticides can be applied using conventional techniques and do not create the problem associated with residues. Baculoviruses infect predominantly holomentabolons insects and almost all pest species within the Lepidoptera are susceptible to infection by at least one of the baculoviruses. Despite their potential, viral insecticides are employed much less than they could be in crops and forests, due to difficulty in virus stability and, most importantly, slower speed of action than that achieved with chemical pesticides.
