Sensibilite des bois de construction des greniers traditionnels aux attaques de Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae)

Abstract

Various wood species used for granary or crib construction were tested for their susceptibility to Prostephanus truncatus (Horn), a new stored grain pest in Benin found in 1984. Ten of the widely used wood species were chosen after survey in infested zones. Wood samples were dried in the oven (60°, 72 hr). They were reduced to 20 cm length, with diameter 2.0–2.6 cm and moisture content varying from 11.1–12.7%, respectively. Wood densities ranged from 0.455–0.999 g/cm−3. Fifty adult insects (<7 days old) were released into the middle of a sample made up of the 10 wood species for free-choice assays and 20 insects per wood species in no-choice tests. Four replicates were set up for each category. After 45 days of exposure at a temperature of 20–35°C and 60–90% r.h., data related to number of Insects that had penetrated each wood, number of larvae, and length of tunnelling were assessed. From the overall data analysis, Elaeis guineensis Jacq. and Holarrhena floribunda (G. Don) appeared least susceptible. Tectona grandis L., Fagara xanthoxyloides Lam., Azadirachta indica A. Juss and Mallotus oppositifolius (Geisel). Mull. Arg. were the more susceptible wood species.