DIETARY EFFECTS ON FITNESS COMPONENTS AT THE PGM-1 LOCUS OF TRIBOLIUM CASTANEUM

Russel A. Riddle ¹, Victoria Iverson ¹, and Peter S. Dawson ¹

¹ Department of Zoology and Genetics Program, Oregon State University, Corvallis, Oregon 97331

The pattern of genetic differentiation among experimental populations of the flour beetle Tribolium castaneum suggested the hypothesis that relative fitness of three genotypes at the PGM-1 locus (or other linked loci) depends directly on diet. This hypothesis was tested by measuring several fitness components (developmental time, survival, fecundity, rate of egg cannibalism) on groups of individuals differing at the PGM-1 locus that were reared on three types of flour (wheat, corn and a mixture of wheat, corn, barley and rye). Flour type had large effects on all traits except larval survival to 3 weeks of age. Relative fitnesses of the three genotypes differed significantly for fecundity. Diet was found to significantly influence the relative developmental times of the three genotypes.