Abstract
Insects and mites infesting wheat. maize, wheat bran and dust samples, stored in or collected from Riyadh and Dammam Provinces, Saudi Arabia, during two seasons, 1987 and 1988, were identified. Of these pests, 16 species of insects were mainly granivorous. Another 26 insect species and 7 mite species were mainly non-granivorous, being either predators, parasites, scavengers or incidentals. The relative abundance of the different species was discussed, and found to be dependent on factors of season, province and type of commodity. ''Common'' species found in both seasons and provinces, included 9 granivorous (4 Trogoderma spp, Tribolium castaneum, Latheticus oryzae, Rhyzopertha dominica, Liposcelis sp. and one Thysanoptera species beside Coleoptera larvae) and 2 non-granivorous (one Cecidomyiidae sp. and Acaropsis sollers) species.