Submitted to: Encyclopedia of Entomology
Publication Type: Book / Chapter
Publication Acceptance Date: 1/9/2002
Publication Date: N/A
Interpretive Summary: This invited chapter is a contribution from a Research Entomologist at the USDA-ARS Western Regional Plant Introduction Station, Pullman, Washington, for the Encyclopedia of Entomology. The audience includes college undergraduates and post-graduates with more sophisticated knowledge. The chapter starts with a general introduction of plant defense emechanisms to insect pests, including the role played by microbial associates of plants, especially endophytic fungi in the genus Neotyphodium, and then moves to a discussion of the nature and extent of endophyte mediated resistance to diverse insect taxa. Researchers are far from fully understanding the range of insect responses to endophyte- infected grasses, yet they have developed a good information base on the outcome of many interactions involving endophyte infection and plant-feeding insects. Today, endophyte-infected grasses are widely deployed on playfields, golf courses, and lawns for insect resistance. This chapter demonstrates ARS involvement and accomplishments in this important area of research.
Technical Abstract: Fungal endophytes (Epichloe species and their asexual Neotyphodium forms) of grasses are one of the best known microbial groups that adversely affect insect survival. These endophytes live for some or all of their life cycle in grasses and are mostly self-perpetuated through material transmission in seed. They are invisible because their host plants show no outward signs of infection. Grass breeders and seed companies quickly develped and marketed endophyte-infected ryegrass and fescue turf grasses in the 1980s after they recognized the benefits associated with endophyte infection. Today, turf grass professionals and homeowners in the U.S. routinely establish infected grasses on golf courses, lawns and playfields for better stand persistence and insect resistance. Both insect deterrence and toxicity result from the production of alkaloids by grass endophytes. An expanding area of investigation at the start of the 21st century involves biotechnological manipulations of endophytes for commercial production of large pools of grass-endophyte associations for insect resistance and other purposes.