Index >> Microbial Products Influencing Plant Growth >> Examples of Known Toxins Involved in Plants Diseases

which is an endotoxin active in inhibiting the growth of about 130 species of insects and larvae. The protein crystal synthesis and spore formation in the bacterium proceed simultaneously and the two processes are in many ways interlinked. The organisms can be grown in naturally available cheap
media (such as bran) and spores harvested to/produce a mixture of spores
and endotoxin crystals. Commercial preparations containing B. thuringien­sis have been produced in many countries notably in U.S.A. where they are used on several agricultural crops, trees and ornamental shrubs.

Other bacterial agents used against insect pathogens are Bacillus popil­
liae, Coccobacillus acridorum and Serratia marcescens.

Fungi and protozoa are also efficient in controlling insect pests on plants. Some of the species of fungi which are currently being used in the U.S.A. in controlling insect pests are Entomophthora spp.., Beauveria spp., Metarrhizium anisopliae and Aeschersonia spp. Examples of protozoans which hold promise as insect pathogens are Thelohania hyphantriae, Mattesia grandis and Malameba locustiae.