Diversity and abundance of entomofauna associated with the cashew tree (Anacardium occidentale L.) and pest damage in the Gbêkê Region (Central Côte d’Ivoire)

The cashew tree represents a strategic resource in Côte d’Ivoire due to its economic importance and high production. However, the entomological complex associated with this crop is still unexplored. This study has been carried out to characterize the abundance, diversity and types of damage caused by insects associated with the cashew tree. Data were collected from 1 June 2023 to 31 July 2024 in a cashew plantation. Field observations were used to identify insect pests and beneficial insects, as well as visible damage to different parts of the tree. The collection was carried out using various methods: by hand, with sweep nets, wine traps and the knock-down technique. The specimens were preserved in 70° alcohol for identification in the laboratory. A total of 6,587 insects were recorded, with a Shannon diversity index (H’) of 3.54 and an evenness index (J) of 0.81. Beneficial insects are dominated by Hymenoptera (54.16%) and Lepidoptera (16.67%). The main pests belong to the orders Hemiptera (43.18%, 19 species) and Coleoptera (38.63%, 17 species), causing damage to the entire tree: young shoots, leaves, inflorescences, fruits and stems. Three functional groups of pests have been identified: stem and root borers (Apate terebrans, Plocaederus ferrugineus), the girdler (Diastocera trifasciata) and sap-sucking insects such as Helopeltis sp., Pseudococcus longispinus, Pseudotheraptus devastans, Pachnoda sp. and Stephanorrhina guttata. Further research is essential to better understand their biology and implement effective integrated pest management strategies, particularly in West African orchards, especially in Côte d’Ivoire.