Dietary Influenced Allozyme Differences between Laboratory Populations of Heliothis virescens

A laboratory population of Heliothis virescens (F.) reared on a lima bean diet is compared with a population reared on a soybean-wheat germ diet. Significant differences in allele frequencies are observed at 3 loci: alphaglycerophosphate dehydrogenase (α-GPHD), hexokinase-a (HEX-A) and hexokinase-b (HEX-B). Experimental populations were established to test the influence of diet and population density on allele frequency changes at these loci. Significant differences in HEX-A allele frequencies are observed between a population maintained for 3 generations on a lima bean and one on a soybean-wheat germ diet. A population maintained for 3 generations on a lima bean diet at normal density and one at a high density show significant differences between HEX-B allele frequencies. Changes at both hexokinase loci are related to a difference in sucrose content of the diets. The cause of α-GPDH allele frequency differences between the 2 laboratory populations was not identified. The different diets cause allele frequency changes at specific loci but do not affect the mean heterozygosity of 19 enzyme loci: 0.247 on lima bean and 0.231 on soybean-wheat germ diets.