Population genetics of haplodiploid insects.

Genic variation of seven species of Hymenoptera is described, using electrophoretic techniques. The heterozygosities range from 0.033 to 0.084. An average heterozygosity is calculated for 23 species of haplodiploid insects, and this value is significantly different from the same value for 18 Drosophila species or for 24 diploid insect species (including Drosophila). The niche width-genetic variation hypothesis is rejected as an explanation. A comparison of selection models and neutral models shows that both hypotheses are capable of explaining the data.