Population growth of Rhyzopertha dominica (F.) (Coleoptera : Bostrichidae)and Tribolium castaneum (H.) (Coleoptera : Tenebrionidae) in different wheat varieties and groups commercially produced in Sonora, Mexico

The population growth of the lesser grain borer, Rhyzopertha dominica (F.), and the red flour beetle, Tribolium castaneum (H.), was determined under l aboratory conditions. Both species were reared using whole grain and flour from four wheat varieties and four wheat groups. Results showed both insect s were capable of completing their life cycles in whole grain and flours fr om all wheat varieties and wheat groups, and all growth stages were detecte d from egg to adult. The adult density of X. dominica all treatments was ve ry low, even though a high initial oviposition was determined. A reduced nu mber of adult T. castaneum resulted when reared in whole grain, but a highe r adult density resulted when reared in flour samples of the different whea t varieties. The correlation coefficients between the chemical characterist ics of all grain wheat samples and growth stages for both insects showed th at starch content had the greatest influence on larval growth, followed by the number of adults and life cycle duration. Total protein contents and ph ysical characteristics did not show a significant influence on the populati on growth of these species.