A comparison of genetic variation in two sibling species pairs of haplodiploid insects.

Sibling species pairs of sweat bees (Halictus confusus and H. tumulorum) and pine sawflies (Neodiprion pratti and N. maurus) were surveyed for genetic variability using enzyme electrophoresis. Levels of heterozygosity were found to be within the ranges earlier recorded for Hymenoptera. Expected heterozygosities were not significantly higher in the sawflies than in the sweat bees. Estimates of genetic identity between the sibling species were not lower than those generally found for diplodiploid insect species: no evidence was found for an increased rate of evolution in these haplodiploids. Genetic identity data among populations of H. confusus and between Halictus species were within the range expected for conspecific populations and sibling species, respectively. In Neodiprion all genetic distances were low but the two populations of N. pratti had similar genetic distances as each did to N. maurus, indicating the necessity for further systematic studies of the genus.