POPULATION DENSITY OF CHIRONOMID SPECIES AND EVALUATION OF SOME INSECTICIDES AGAINST LARVAE AT KAFR EL-SHEIKH GOVERNORATE RICE FIELDS

This study was carried out at El-Sabein village, Sidi Salem District, Kafr El-Sheikh governorate during two successive seasons; 2014 and 2015 for studying the population fluctuations of the rice bloodworms, Chironomus spp. and evaluating three insecticides against the chironomid larvae at rice nursery. The population density of Chironomus spp. exhibited two peaks in each season. Diazinon was the most efficient insecticide in reducing the population density of Chironomus spp. larvae with reductions of 88.62 and 89.85% after 24 hours of treatment while the reductions were 87.14 and 89.42% after 7 days in the two seasons of study respectively. It was followed by Lambada- cychlothrin while Emamectin benzoate was the least effective compound that gave reductions of 76.48 - 77.56% and 79.09 - 82.94%.