Survey of some rice insect pests and their predators in three districts of Sri Lanka

Sampling for planthoppen, leafhoppers and other minor pests was carried out in rice fields, kept free of insecticides, in the districts of Batticaloa, Kilinochi and Jaffna, during Maha 1981-82 and Yala 1982, using the sweep net technique. The brown planthopper Nilapawata Iugens (Stal) was recorded in Batticaloa and Jaffna districts and Sogatella furcifera Horvath in- Kilinochi. The leafhoppers Nephotettix virescens (Distant) and Nepbotettix nigropictus (Stal) were recorded from all three districts. The minor pests collected included Leptocorisa oratonus (Fabricius), Scotinopbora lurida Burmeister, Nauru viridula Linnaeus, Tanymecus sp., Aulacopbora sp., Acrididae, Tettigoniidae and Gryllidae. Insect predators recorded were Cyrtorbinus lividipennis Rcuter, two Coccinellids Micraspsis discolor and Harmonia octomaculata, a Staphylinid Paederus fuscipes Curds and an Anthocorid. Other general predators observed belong to the Odonata - Lestes sp., Pseudap'on sp., Ortbetrum sp. and Anax sp.