Effect of Azadirachtin A systemic injection on Coelaenomenodera lameensis Berti and Mariau (Coleoptera: Chrysomelidae) an oil palm (Elaeis guineensis L) pest

Coelaenomenodera lameensis is the major pest of oil palm. The fight against this pestis achieved by using several methods including the injection of systemic insecticide inthe trunk of the palm. The tests were conducted at the agro-industrial units ofToumanguié, located 90 km from Abidjan. Azadirachtin A was used in systemictreatment at four concentrations: 0.1, 0.2, 0.4 and 0.6 g/ml. Chiffon sleeves wereplaced on the palms to assess the effect of products on C. lameensis. Systemicinjections were made during the dry and rainy seasons. The efficacy of azadirachtinwas assessed by reference to thiamethoxam, an insecticide used in the fight against thispest. The effective minimal concentration was 0.4 g/ml of azadirachtin. Thisconcentration generated the cumulated mortality rates of 38.92% in dry season and19.28% in rainy season on the adults after 28 days of treatment. The percentages ofefficiency achieved in the dry season on the larvae 7 days after treatment were 74.75%(stage 1), 57.23% (stage 2), 7.14% (stage 3) and 5.31 % (stage 4). In rainy season, theefficacy of azadirachtin on larvae was less than 29%. Azadirachtin can be used in dryseason, at the beginning of the infestation period, to fight against C. lameensis