OCCURRENCE OF GREENBUG (HOMOPTERA, APHIDIDAE) BIOTYPE-E AND BIOTYPE-I IN KANSAS, TEXAS, NEBRASKA, COLORADO, AND OKLAHOMA

Greenbugs collected from Kansas, Texas, Nebraska, Colorado, and Oklahoma were tested to determine the occurrence of greenbug, Schizaphis graminum (Rondani), biotypes E and I in sorghum and wheat from 1991 through 1993. The occurrence of biotype I appears to be widespread in the Texas panhandle and in Kansas. Biotype I appears to occur more frequently in southwestern Kansas than other areas of Kansas. An intensive field survey was conducted in 1992 and 1993 to determine occurrence of the two greenbug biotypes within 10 randomly selected sorghum fields in southwestern Kansas. Biotype I occurred in ail but one intensively sampled field.