Insect pest dynamics according to the phenological stages of millet (Pennisetum glaucum) in the Maroua agroecosystem (Far North Region of Cameroon)

The insect pest dynamics was study according to the phenological stages of millet on the CHACKTI and Sl28 varieties. The study, which focused on the inventory of millet insect pests in the irrigated agroecosystem of Meskine, allowed us to inventory millet insect pests in the irrigated millet agroecosystem of Meskine in the Far North region. This inventory allowed us to identify several insect species in the orders Coleoptera, Diptera, Hemiptera, Lepidoptera, Odonata, Hymenoptera, and also the order Araneae, associated with these ecosystems. Twenty insect species belonging to eleven families and distributed across seven orders were collected from the irrigated millet of Meskine. The number of insects captured was significantly higher at the seedling and maturity stages, with a difference of 934 insects compared to the other tillering and heading stages. Among the species collected on millet, the Nephottetix nigropictus species from the Hemiptera family is the most abundant. The insects that cause the most damage are Nephottetix nigropictus, Graptasthetus lectus, Altica sp., Cletus sp., and Diploxys acanthura, belonging to the orders Hemiptera, Diptera, and Coleoptera. Maliarpha separatella and Sesamia calamistis are chewers in the larval stage (caterpillar); their larvae and Diopsis sp. are stem borers that have caused significant damage to millet plants. The most represented orders are the order Coleoptera, with four species: Chnootriba similis, Cheilomenes lunata, Tribolium casteneum, and Altica sp. and the Diptera order with 4 species: Diopsis sp., Diploxys acanthura, Graptastethus lectus and the least represented orders are the Odonata order with two species: Lestes sp. and Palpopleura sp., the Hymenoptera order with two species: Bracon sp. and Platygaster sp. It is also noted that all varieties are vulnerable to pest attacks throughout the growing cycle. In addition to the presence of millet insect pests, some species of natural enemies were recorded, namely predators and parasitoids.