Inventory of entomofauna associated with crop of okra (Abelmoschus esculentus) and assessment of damage caused by insect pests in Man, west of Côte d'Ivoire

Abstract

Okra (Abelmoschus esculentus) is one vegetable crops most cultivated in Côte d'Ivoire. However, the plant is attacked by insects which caused important damage. This study was carried out to inventory entomofauna associated with okra crop and assess the damage caused by the pests. The insects were captured using pliers, sweep net by mowing technique and colored traps. Overall, a total of 61 species belonging to 36 families grouped into 10 orders were identified. During the plant cycle, 11602 insects were collected, including 3663 individuals at before stage flowering (31.57%); 3757 individuals at the flower bud stage (32.38%) and 4182 individuals at the flowering-fruiting stage (36.05%). Analysis of the occurrence frequency showed that Podagrica decolorata was ubiquitous in the crop, causing considerable damage to all organs of the plant. The damage assessment revealed that the defoliators, induced the highest average attack rates at all phenological stages. During the collections, six species (Rhinocoris albopilosus, R. rapax, R. bicolor, Hediocoris fasciatus, Cosmolestes pictus and Coranus sp) belonging to the family of Reduviidae were identified as predators of P. decolorata. This study therefore made it possible to identify P. decolorata as a major pest of okra and its predators, thus opening up a perspective of biological control as an alternative to chemical control.