Greenbugs: Determining Biotypes, Culturing, and Screening for Plant Resistance, With Notes on Rearing Parasitoids

Characteristics for separating the four biotypes (A, B, C, and D) of the greenbug, Schizaphis graminum (Rondani), are discussed, including morphological differences and response to resistant varieties and insecticides. Techniques for culturing greenbugs on caged plant:; in the greenhouse are described. In addition, methods are suggested for screening for plant resistance both in the greenhouse and in the field. Sources of plant resistance to the greenbug are listed. Culturing techniques for both primary and secondary parasitoids are covered. Difficulties that may be encountered are discussed for all phases of rearing and screening.