Pathogen incidence and their potential as microbial control agents in IPM of maize stem borers in West Africa

A review of the existing basis for maize stem borer IPM is given and the ro le of pathogens in the system is evaluated. Survey work outlining the major groups of insect pathogens is described; fungi (Beauveria bassiana and Met arhizium anisopliae), bacteria (Bacillus thuringiensis and Serratia marcese ns), and viruses (granuloviruses and cytoplasmic polyhedroviruses) were ide ntified. The presence of other unidentified protozoans, nematodes, fungi an d viruses was noted. The virulence of some of the more promising known inse ct pathogens was explored in preliminary bioassays. Considering the cryptic habits of the insects, and the low input agriculture practiced by the majo rity of maize farmers in sub-Saharan Africa, Beauveria bassiana isolates po ssessing the capacity to grow systemically in the maize plant are considere d one of the more interesting candidates for development as microbial contr ol agents despite limited control in preliminary trials. Further work shoul d also investigate the potential of pathogens of moderate virulence, such a s the protozoans and CPVs.