Abstract

Pseudotheraptus devastans (Heteroptera: Coreidae) is a coconut pest in Côte d'Ivoire. Various larval stages and adults cause deformation of young nuts, sometimes leading to them falling off. The search for a strategy to protect these nuts involved evaluating the efficacy of essential oils of Eucalyptus citriodora and Lippia multiflora on P. devastans. Present study was carried out at the coconut research station of the Centre Nationale de Recherche Agronomique of Côte d'Ivoire. The tests were carried out by spraying EOs at different concentrations on P. devastans larvae and adults. Lethal concentrations causing the death of 50% (LC50) and 90% (LC90) of the populations tested were determined for each of the EOs. EOs had variable effects on the two developmental stages of the insect. Oil extracted from E. citriodora was more toxic, with respective values of LC50 = 0.04%, LC90 = 0.30% for larvae and LC50 = 1.24%, LC90 = 2.43% for adults, compared with that extracted from L. multiflora (LC50 = 0.17%, LC90 = 6.43% for larvae and LC50 = 3.51%, LC90 = 27.57% for adults). Its use in the field can, therefore, be suggested for the control of this coconut pest.