Abstract
Populations of the green rice leafhopper, Nephotettix cincticeps, sampled from five regions in Miyagi Prefecture in 1988 and 1989 were less susceptible to malathion, fenobucarb, carbaryl and propoxure than populations collected in 1971. The population at Rokugou, Sendai sampled in 1989 was 161-times less sensitive to malathion than the 1971 population. Despite fewer insecticide applications, susceptibility to malathion, fenobucarb and carbaryl decreased in populations of two regions. Resistance to these insecticides may be related to the extent of control by propoxure and carbosulfan used as systemic insecticides.
