Scientific publications
Sadou Ismael
Samy Eware Mbongaya
Noé Woïn
Richard Ghogomu
To develop a biological control method of fight, an inventory of predators and parasitoids of insect pests of rice (Oryza sativa and Oryza glaberrima) was conducted in three agro-ecological zones in far North region of Cameroon (Sudanian, Sahelian and Sudano-Sahelian). The insects and spiders was trap using a sweep net and a D-Vac (aspiration trap) which was performed every two weeks in rain fed rice on a site (Maroua) from June to September 2012 and the irrigated rice at two sites (Yagoua and Maga) from October to December 2012 in the phenological stages of rice following: nursery, tillering, heading and maturity of rice. The following pests were collected at different stages of rice growth in irrigated and rain fed rice: Chnootriba similis (Coleoptera: Coccinellidae), Chaetocnema pulla (Coleoptera: Chrysomelidae), Trichispa sericea (Coleoptera: Chrysomelidae), Locris rubra (Hemiptera: Cicadellidae), Nephotettix nigropictus (Hemiptera: Cicadellidae), Sogatella furcifera (Hemiptera: Delphacidae), Cofana spectra (Hemiptera: Cicadellidae), Recilia dorsalis (Hemiptera: Cicadellidae), Niparvata lugens (Hemiptera: Delphacidae) and Diopsis thoracica (Diptera: Dipsidae). Regarding the populations of predators, spiders (Araneae) were the most abundant (Araneus spp., Tetragnatha spp. and Pardosa injucunda), with the high competition of the Araneus spp. in all the sites. The inventory shows that the abundance of insect predators varies with different growth stages of rice. Thus at Yagoua more predators (Araneus spp.) were collected during the tillering stage of rice. In parasitoids, Hydrellia griseola (Diptera: Ephydridae), Bracon spp. (Hymenoptera: Braconidae), Xiphosomella spp. (Hymenoptera: Braconidae) and Platygaster spp. (Hymenoptera: Platygasteridae) were inventoried. The inventory of parasitoids in different rice sites suggests that these species also varies with different phenological stages. Indeed, in Maroua more parasitoids were collected during the tillering stage of rice. Of these parasitoids only the Hydrellia griseola (Diptera: Ephydridae) species was caught in abundance in the tillering stage of rice in the three sites. The results of this study indicate a potential biological control against insect pests of rice using predators and parasitoids. This potential should be developed to manage the yield losses caused by insect pests of rice.
