Egg and nymphal parasites of rice leafhoppers and planthoppers. A result of field studies in Taiwan in 1979 (Part 1).

Results of field studies of egg and nymphal parasites of Sogatella furcifera, Nilapalvata lugens and Nephotettix nigropictus made in Thailand in 1977 are presented. Two species of egg parasites, Oligosita sp. and Anagrus optabilis, were reared from Sogatella furcifera, 1 species of egg parasite, Anagrus optabilis, was reared from Nilaparvata lugens, and 2 species of egg parasites, Paracentrobia sp. and Gonatocerus sp. were reared from Nephotettix nigropictus. Paracentrobia s p. a nd Gonatocerus sp. were found to be ecologically similar species inhabiting the same rice paddy and parasitize even the same egg-mass of Nephotettix nigropictus. Lar vae of dryinid wasps were detected from Sogatella furcifera, Nilaparvata lugens and Nephotettix nigropictus. Stylopids were a lso de tec ted f rom the 3 r ice hoppers mentioned above. Nephotettix nigropictus is recorded as a new host of Strepsiptera in Thailand. This paper reports one of the results of our field studies on the natural enemies of rice leafhoppers and planthoppers made in Thailand from October to December, 1977. Only the insect parasites attacking eggs, nymphs and adults of three important rice hoppers, Sogatellu furc(feera, Nilaparvata lugens and Nephotettix nigropictus, are dealt with in this paper. Acknowledgement: We are very grateful to Dr. K. Yasumatsu, Emeritus 1)