Comparative synergetic effect of coconut palm (Cocos nucifera L.) slices and bunches residue of oil palm (Elaeis guineensis JACQ.) associated with two kinds of pheromone traps on Oryctes monoceros OLIVIER trapping in Côte d'Ivoire.

Oryctesmonoceros (Coleoptera, Dynastidae) is one of the most danger ous pests of coconut palm and oil palm plantation in Côte d'Ivoire. In order to create a method to reduce these pests' populations, a trapping trial with the pheromone was carri ed out for 4 months in the seed garden of the station "Robert Michaux" from the CNRA (Centre National de RechercheAgronomique). Two kinds of traps (PVC tube and buckets), using pheromone 4 - methyloctanoate ethyl associated with coconut palm slices or bunches residue of oil palm as attractive materials were tested. Coconut stem slices were used two and half months after felling the palms. The bunches residue of oil palm where taken one week after the machining. To assess the daily and monthly quantities of diffused pheromone, diffusers were weighed at the setting up of the experiment, t hen every month for 4 months. The traps were observed every 3 days by collecting the captured Orycte s . The number of the Oryctes captured in PVC tube varied from 15 to 18 as against 12 in buckets during the first three months, whatever the associated syner getic material. Coconut palm slices must be recommended to farmers, because associated with pheromone, they allowed the capturing of more Oryctes than bunches residue of oil palm. The replacement of the pheromone must take place every 3 months. Beyond suc h a delay, pheromone diffusers empty. The mass capture with pheromone allowed the effective controlling Oryctes in coconut farms. (Résumé d'auteur