ABSTRACT
This chapter discusses the microbial agents which have received most research and development as microbial controls for turfgrass and ornamental insects. Naturally occurring insect disease organisms provide a potentially rich source of control options for use in plant protection for ornamental and landscape plants. The area which has received the least attention in ornamental plant protection, as well as in agriculture, is manipulations which conserve or enhance naturally occurring levels of an insect pathogen. Insects which tunnel into plants are not well controlled, even though they may be susceptible to the Bt toxin. Several important groups of plant pests are attacked by virus diseases. Among the most important are the baculoviruses which attack many leaf-feeding caterpillars and sawflies that are damaging to ornamental and forest plants. The appropriate use of Nosema locustae in ornamental plant protection is as a grasshopper management tool, for long-term suppression.
