Diversity and Abundance of Pest Insects Associated with Solanum tuberosum L. 1753 (Solanaceae) in Balessing (West-Cameroon)

Solanum tuberosum L. 1753 (Solanaceae) is widely cultivated for its therapeutic and nutritional qualities. In Cameroon, the production is insufficient to meet the demand in the cities and there is no published data on the diversity of associated pest insects. Ecological surveys were conducted from July to September 2020 in 16 plots of five development stages in Balessing (West-Cameroon). Insects active on the plants were captured and identified and the community structure was characterized. The abundance of each species and the part of the plant attacked were recorded. A total of 370 specimens belonged to four orders, 16 families and 21 species. From rearings of 3,200 scarified stems and tubers, two Lepidoptera emerged: the Crambidae Leucinodes orbonalis Guenee, 1854 (18.0%) and the Noctuidae Helicoverpa armigera Hubner, 1808 (26.0%). This gives a total of five orders, 18 families and 23 species associated with the potato plants. We recorded 16 (69.6%) pest species [10 (43.5%) non-native and six (26.1%) native species]. Base on the family composition, Coleoptera and Hemiptera were mostly represented (31.3% respectively) followed by Orthoptera (25.0%) and Diptera (12.4%). Based on the species composition, Hemiptera presented a high number of species (38.1%) followed by Coleoptera (28.6%), Orthoptera (23.8%) and Diptera (9.5%). Based on abundances, Aphididae (60.6%) was the most represented, followed by Gryllotalpidae (7.6%), Tenebrionidae (6.5%), Bibionidae (5.7%), Gryllidae (4.9%), Pentatomidae (4.9%), Cicadellidae (3.5%) and Pyrgomorphidae (2.4%). Eight rare families were recorded (<1% of the total collection respectively) (Acrididae, Chrysomelidae, Elateridae, Lycidae, Scarabeidae, Scutelleridae, Tipulidae and Pyrrhocoridae). Chemicals were not efficient in the study locality, since entomofauna associated with potato plants remained diverse and consisted of alien pests. The situation calls for more research on the bio-ecology of the recorded pests with further goal of developing sustainable management strategies to reduce yield losses.