Présence, populations et dégâts de l’alucite des céréales Sitotroga cerealella (Olivier) (Lepidoptera,Gelechiidae) sur les stocks de riz au Bénin

Abstract

Presence, population and damage of the angoumois grain moth, Sitotrogacerealella (Olivier) (Lepidoptera, Gelechiidae), on rice stocks in BeninTheangoumois grain moth, Sitotrogacerealella (Olivier) (Lepidoptera, Gelechiidae) is a major pest on several continents causing major damage to stocks of several cereals(rice, maize, sorghum etc.). This study aimed at analyzing the presence of S. cerealellain key sites of rice production in Benin and evaluating the level of the pest populationand its damage to farmers’ rice stocks. For this purpose, paddy rice samples were collectedfrom 11 sites of peasant stockage. In addition, pheromone traps were placed in farmers’paddy fields to study infestations. The resultsshowed that 70 % of the rice stockswere infested by S. cerealella, with average populations varying from 30 to 300 individualsper kg of paddy. In infested samples, the damage level ranged from 3% to 18 % ofgrains attacked for 2 to 4 months of storage. Pheromone trapping showed that 80 % ofthe rice fields were infested, with an average of 16 individuals captured per trap. Thepresence of this pest is thus confirmed on rice in Benin. This study also shows thatimportant damage can be caused on stored rice as soon as the storage period reaches 3to 4 months