Influence of cocoa cultivation on the diversity and density of termites in the Azaguié zone (South of Côte d’Ivoire)

Abstract

Termites play an important role in the aeration and fertilization of soils where they abound. However, cultural practices influence their ecology. This study, which took place in Azaguié in the south of Côte d'Ivoire, aimed to know the diversity of termites that colonize cocoa plantations in comparison with the natural area. Three age classes of plantations have been defined: PC1 (from 0 to 5 years), PC2 (6 to 10 years old) and PC3 (over 30 years old). In each class of plantations, three transects 100 m long each, subdivided into 20 sections of 10 m2 (10 m x 2 m) have been demarcated. Three (3) monoliths were also dug by transect in order to know the density of hypogeal termites. Old plantations were more diversified with 18 species compared to plots PC1 (14 species) and PC2 (16 species). The natural area recorded the highest specific richness with 21 species sampled. The relative abundance of fungal termites in transects showed a high adaptability of these insects (18 occurrences in plots PC1 to 26 occurrences in natural area). With hypogeal termites, 16 species have been collected in all habitat types. The Jaccard Similarity Index showed large differences between species of hypogenous termites according to habitat types. No significant difference was observed between termite densities in selected plots. However, the distribution of termites in the depth of the soil was unevenly distributed and the surface layer of 0 - 10 cm concentrated the majority of termites. Cocoa production influences termite diversity and density, but the cessation of agricultural activities results in the recomposition of termite biodiversity.