Trapping the rusty grain beetle, Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae), near and far from grain storage bins

The rusty grain beetle, Cryptolestes ferrugineus, is a common and serious pest of stored grain that has evolved resistance to the grain fumigant phosphine.  This stored grain pest infests bins where grains or grain products are stored, but it is not known if they disperse long distances by flight to infest new bins and facilitate spread of phosphine-resistance genes.  Two studies of C. ferrugineus flight and orientation were conducted in wheat-growing sites with small storage bins west of Manhattan, KS.  The first study used open 18.9 liter buckets containing .67 kg of soft white winter wheat as a bait source for beetles flying outside stored wheat bins.  Four buckets were placed 6 m from each of three storage bins located on three different sites, and buckets were positioned at each of the four cardinal directions around the bin.  Weekly bucket counts revealed that most beetles were found north and west of the bin being monitored.  Flight of C. ferrugineus at longer distances from bins was examined using an aggregation pheromone.  Lindgren multiple funnel traps with wheat in a mesh bag were used to test synthetic “cucujolide-II” as an attractant for in-flight beetles. Replicated studies found that more C. ferrugineus responded to pheromone plus wheat than to wheat only. Thus pheromone traps will be used in future studies.