Genetic variability associated with hovering time in Tabanus nigrovittatus Macquart (Diptera: Tabanidae)

The salt marsh horse fly, Tabanus nigrovittatus Macquart, exhibits two non-overlapping daily periods of hovering and mating activity, which are correlated with different environmental temperatures. Allelic and genotypic frequencies of hovering males collected during the two periods were compared by electrophoresis of three polymorphic enzyme loci. Approximately 26% of early-hovering males possessed a Pgm allozyme that was absent in our sample of late-hovering males. However, based on other allozyme loci, we found no evidence for reproductive isolation between early and late hoverers. All the genetic data are consistent with the hypothesis that the Pgm polymorphism is associated with behaviorally and physiologically distinct groups of males that, by all other criteria, form a single Mendelian population.