Genetic analysis of a population of Tribolium. V. Viability of the unsaturated fatty acid sensitive mutant.

The viability pattern of the unsaturated fatty acid sensitive mutant (cos/cos) of Tribolium castaneum was examined with reference to the normal genotype from egg hatching through adult emergence. The beetles were cultured on diets with 0, 3, or 5% corn oil in growth chambers maintained at 33 +/- 1 degree C and either 42 +/- 6% or 75 +/- 3% relative humidity. The pattern of the mutant was altered during the larval stage and was dependent on both the concentration of dietary fatty acid and the relative humidity of the culture chamber. Values of the viability component of fitness were assigned to the cos/cos, +/-/cos and +/-/+/- genotypes for multiple environments based on the number of eggs surviving to pupation. In large, random mating populations segregating at this locus, a stable genetic polymorphism is forecast. Predicted rates of change of allele frequency are dependent upon the culture conditions.