Diversity and Abundance of Pest Insects Associated with Capsicum chinense (Jacq. 1776) (Solanales: Solanaceae) in the Locality of Bini (Ngaoundere-Cameroon)
Abstract
The exotic Capsicum chinense Jacq., 1776 (Solanaceae) is damaged in farms by insects in Ngaoundere (Cameroon). During ecological survey (from April 25 to August 25, 2024) in 44 neighboring plots of 4x3.5 m each, plants were inspected and adult insects found on stems, leaves, flowers and fruits were counted and captured using either a mouth aspirator or fine forceps for small sized non-flying specimens, or a dip net or butterfly net for large sized flying specimens. Four daily-checks spaced by a five-minute break, were carried out one day per week, four weeks per month and four months. Captured specimens were stored in vials containing 70% alcohol, identified to species level in laboratory and the community structure was characterized. A total of 48,298 specimens belonged to seven orders, 12 families, 14 genera and 14 species. Hemiptera was the most recorded (45.1% of the total collection) followed by Thysanoptera (43.5%), Orthoptera (7.6%), Coleoptera (2.1%), Hymenoptera (1.3%), Lepidoptera (0.2%), and Mantodea (0.2%). Aleyrodidae (Hemiptera) and Thripidae (Thysanoptyera) were mostly recorded. Aleurotrachelus trachoides (Aleyrodidae) was the most recorded (44.7%) followed by Heliothrips haemorrhoidalis (Thripidae) (43.5%), Tagasta marginella (Pyrgomorphidae) (5.8%), and Xenocatantops humilis (Acrididae) (1.3%), other species being rare. Three rare species were natives: Apis mellifera (Apidae), Bagrada hilaris (Pentatomidae), and the pest Lagria villosa (Tenebrionidae). Eleven species (78.6% of the total species richness, 98.3% of the total collection) were exotics. Three useful species were recorded: two pollinator Apidae Amegilla sp. and Ap. mellifera and the eggs-predator Carabidae Laemostenus complanatus. Five exotics were pests: Al. trachoides, Grapholita (Aspila) funebrana (Tortricidae), Gryllus campestris (Gryllidae), H. haemorrhoidalis, and Luprops tristis (Tenebrionidae), A lowspecies richness with a median level of species diversity, median evenness and dominance were detected. Three exotics Al. trachoides, H. haemorrhoidalis, and T. marginella were abundant and co-dominants. Assemblage functioned like a pioneer community and C. chinense appeared to attract naturalized exotic pests. Due to the dominance of non-natives, once they would monopolize available resources and saturate the locality, they would not allow natives the niche opportunities to re-establish themselves. The consequences of loosing natives, which may well interact with the endemic flora and fauna, will be of extreme concern.