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, W est Africa Dinoderus bifoveolatus Wollaston was the predominant pest. In ol factometer experiments, cassava chips infested by male D. bifoveolatus were highly attractive to both sexes of the beetle, suggesting that male D. bif oveolatus produce an aggregation pheromone. Female D. bifoveolatus showed a significantly stronger response pattern than conspecific males. Sticky tra ps, baited with cassava chips harboring male D. bifoveolatus, set up in 2 r egions of southern Benin, consistently caught considerable numbers of consp ecifics. Trap catches differed significantly between the regions, and for 1 region also between the sites. The sex ratio of the trapped D. bifoveolatu s was significantly female biased. Low numbers of 2 other bostrichids [i.e. , Prostephanus truncatus (Horn) and Rhyzopertha dominica (F.)] were also re corded in the traps.