FIELD STUDIES ON THE BIOLOGICAL CONTROL OF LEAFHOPPERS AND PLANTHOPPERS (HEMIPTERA : HOMOPTERA) INJURIOUS TO RICE PLANTS IN SOUTH-EAST ASIA. PROGRESS REPORT FOR THE YEAR 1977

Abstract

INTRODUCTION Rice leafhoppers and planthoppers have been an important menace to rice in Asian countries not only because of their severe damage due to their abundance but also of their ability to transmit virus diseases of this important food plant. Control of these homopterous insect pests includes many difficult problems. In the field of biology, the development of various biotypes of the brown planthopper recently observed in some Asian countries is apparently one of these. In Japan, outbreaks of the white-backed planthopper and the brown planthopper due to their long distance trans-ocean migration have been one of the most serious problems in applied entomology for many years. Some important species of the rice hoppers occur throughout Asia, and each country has nearly the same problems with these pests. Thus, it is understood today that cooperative studies among countries concerned can only contribute toward successful control of these pests. Our project aims at to find out primarily insect natural enemies as well as pathogens of microbial diseases of rice leafhoppers and planthoppers in countries in SouthEast Asia in order to conrtibute &ward the basic study of the ' biological control of these pests.