Assessment of Insect Pest Pressure in Cashew Orchards (Anacardium occidentale L.) in Marahoué Region, Bouaflé, Côte d’Ivoire

ABSTRACT: This study aims to transition the prevailing extensive cashew nut cultivation model into a more sustainable farming approach that enhances tree productivity. To achieve this, insect pest populations were surveyed across three orchard age categories: young orchards (0-5 years), intermediate orchards (5-10 years) and mature orchards (over 10 years), each covering an area of 1 hectare. For each age group, 5 orchards were selected, and in each orchard, an arrangement of 10 consecutive cashew trees chosen at random in the direction of the north-east diagonal was set up. Parasitic pressure parameters were then assessed and determined. A total of 70 insect pests divided into six orders were collected in all the orchards sampled. On average, 43.33% of the cashew seedlings analyses fell victim to insect attack, a proportion that proved higher in orchards aged 0-5 years, where 70% of trees were affected. These young orchards also showed the greatest abundance (32 individuals) and diversity (15 species) of pests. Overall, organ vulnerability was characterized by attack rates reaching 100% for trunks, 54.11% for branches and 8.7% for buds. In addition, a significant variation in parasite pressure was noted according to the different types of orchards sampled. However, orchards more than 10 years old showed significantly better agronomic performance (fruiting and production rates) than younger orchards (0-5 years and 5-10 years). Young orchards require adequate technical support, the lack of which often results in the neglect of pruning and coppicing operations on young plants, leading in particular to a significant accumulation of deadwood. Careful application of these compensatory measures will help increase both the volume and quality of floral resources, as well as increasing the presence of beneficial insects, thereby optimizing the agronomic yields of the various orchards.