Bacteria as biological control agents for insects: Economics, engineering, and environmental safety

Abstract

Pathogens of insects have been under evaluation as biological control agents for more than a century. With few exceptions, they are not effective as classical biological control agents. Moreover, even as insecticides, only Bacillus thuringiensis (Bt) has been a commercial success. Bt's success, in essence, is due to its ease of mass production by fermentation on inexpensive media, which facilitated commercialization. Viruses, fungi, and protozoa are used in only a few niche markets, and thus have largely failed as microbial insecticides, and will continue to fail until more efficacious mass production methods are developed. Despite these failures, research on insect pathogens led to the development of transgenic insect-tolerant Bt crops, arguably the most important advance in pest control technology of the latter half of the 20th century. Numerous laboratory and field studies have shown that these crops are cost-effective and much safer than synthetic chemical insecticides for the environment and non-target organisms. The high specificity of Bt crops provides a new cornerstone for biological control and sustainable agriculture that will enable both to expand during this century. © 2007 Springer.