EFFICACY OF TWO BIOPESTICIDES NECO 50 EC AND LIMOCIDE 60 ME ON COELAENOMENODERA LAMEENSIS (COLEOPTERA, CHRYSOMELIDAE: HISPINAE), THE MAIN PEST OF OIL PALM (DALOA, COTE DIVOIRE)

Abstract

Coelaenomenodera lameensis (Coleoptera: Chrysomelidae, Hispinae), the leafminer of oil palm, is the most feared insect for this crop in Côte d'Ivoire. The aim of this study was to evaluate the efficacy of two biopesticides (NECO 50 EC and LIMOCIDE 60 ME) on C. lameensis adults. Trials were carried out under controlled infestation on an oil palm plot at the University Jean Lorougnon Guédé in Daloa. To assess the insecticidal effect of the products, male and female adults of C. lameensis were introduced into cages placed on palms containing palm leaflets. These adults were sprayed 48 hours later, at concentrations ranging from: 1.92×10-3 to 8.33×10-3 g/ml (NECO); from 3.58×10-4 to 1.75×10-3 g/ml (LIMOCIDE) and from 3.02×10-4 to 2.07×10-3 g/ml (Sivanto Energy, chemical reference insecticide). Controls were carried out from the 1st to the 15th day after treatment. NECO 50 EC induced maximum mortality rates of 100% (females and males) from day 4 after treatment. For LIMOCIDE, concentrations of 8.9×10-4 g/ml and 1.75×10-3 g/ml respectively induced mortality rates reaching 100%(females) on days 13 and 10 post-treatment. In males, only the 1.75×10-3 g/ml concentration produced mortality rates of 100% on day 12. In the case of Sivanto Energy, mortality rates of 100% (females and males) were recorded as early as day 2 at a concentration of 8.42×10-4 g/ml. Lethal Concentrations (LC50) were 4.96×10-3 g/ml (females) and 5.37×10-3g/ml (males) for NECO, 1.15×10-3g/ml (females) and 1.38×10-3 g/ml (males) for LIMOCIDE. These two biopesticides could be used as an alternative to the abusive use of synthetic insecticides to reduce C. lameensis damage and increase palm oil production in Côte d'Ivoire.