Influence of three factors on the establishment of an Oecophylla population for the biological control of the coconut bug in lowland Côte d'Ivoire.
Pseudotheraptus devastans is the cause of important localized damage on coconut in Cote d'Ivoire. The biological control of this insect was conducted with the use of a natural enemy called oecophylla (Oecophylla longinoda). The population of oecophylla on coconut trees was accelerated with the construction of bridges between colonized and non-colonized trees. Forest regrowth allowed the oecophylla population to increase by 2-fold in uncleaned plots. However, in regularly cleaned plots, the population was considerably reduced. Black ants of the genus Camponotus had an antagonistic effect on red ants. These black ants did not allow the establishment of O. longinada when present on the coconut trees. For the recolonization of trees, a localized chemical treatment must be applied beforehand. The dry season was found to favour the protective potential of O. longinoda. This protection was shown by the high population rate of oecophylla. During the rainy season, the population rate was found to be low.