Central Insecticides Laboratory, Directorate of Plant Protection, Quarantine and Storage, NH-IV, Faridabad-121 001 (India).
Ovicidal action of fenvalerate, cypermethrin, monocrotophos and triazophos against 1,2,3 and 4-day old eggs of D. koenigii and their residual toxicity on emerging nymphs were studied in the laboratory. The higher dosages of these insecticides showed comparatively better lethal action on eggs and emerging nymphs. One-day old eggs were less susceptible to these insecticides as compared to 2, 3 and 4-day old eggs. On the basis of per cent decline in progeny, triazophos was the most toxic insectlclde to the eggshymphs of D. koenigii as compared to cypermethrin, fenvalerate and monocrotophos.
