Host-Finding Behavior of Dinoderus bifoveolatus (Coleoptera: Bostrichidae), an Important Pest of Stored Cassava: the Role of Plant Volatiles and Odors of Conspecifics

In cassava chips sampled on a local market in Cotonou, Republic of Benin, West Africa, Dinoderus bifoveolatus Wollaston was the predominant pest. In olfactometer experiments, cassava chips infested by male D. bifoveolatus were highly attractive to both sexes of the beetle, suggesting that male D. bifoveolatus produce an aggregation pheromone. Female D. bifoveolatus showed a significantly stronger response pattern than conspecific males. Sticky traps, baited with cassava chips harboring male D. bifoveolatus, set up in 2 regions of southern Benin, consistently caught considerable numbers of conspecifics. Trap catches differed significantly between the regions, and for 1 region also between the sites. The sex ratio of the trapped D. bifoveolatus was significantly female biased. Low numbers of 2 other bostrichids [i.e., Prostephanus truncatus (Horn) and Rhyzopertha dominica (F.)] were also recorded in the traps.