Evaluation of the efficiency of aqueous extract of neem fruits on insect pest of rice in rice agroecosystem of Maga in the far north region of Cameroon

The chemical fight against insects pest causes many problems on the biodiversity of ecosystems, destabilizes the trophic level of the ecosystem and has harmful effects on the on health human. Mean while the biological fight using plants extractions can equally play the same role of killing pest, reason why the present study which was carried out in the irrigated perimeters of Maga in the Far North region of Cameroon, have as principal objective to evaluate the aqueous extraction of neem fruit on the insects pest of rice. The specific objectives were to know the biological diversity of insect pest in the irrigated perimeters of Maga, and their repartitioning in the phenological stages, again, to see the effects of the aqueous extractions of the neem fruits on the insects pest per variety and in function of the phenological stages, also to evaluate the damages cause by insects pest during the talling stage in function of the varieties, finally, to evaluate loss cause by the insects pest. The study was made on two rice varieties which were IR46 and NERICA3 in a split plot disposition. The capturing of the insects was done with the help of a sweep net and the identification of the species was done with the help of an entomological buttle, the identification key of insects by Heinrich (1993), Hill (1983), Heinrichs and Barrion (2004) and the families recognition keys by Delvare and Aberlenc (1989).The method of Breniere permited the estimation of loss of output at the talling and harvesting stages of rice caused by the insect pest. The analysis of variance of the result was done using SPSS 20. In the class of insects, twenty two species of insects fall in twenty families divided in seven orders were collected. Among the captured insects, we investigated fourteen insects which were pest. The biological fight have shown an effectiveness in the nursery, talling, and a positive and non negligible effects on the reduction insects pest in the heading and maturation stages and thus has permitted the reduction of damages from insects on the rice plants.