Print PageThe Pallid Dotted-Blue (Euphilotes pallescens), a butterfly in the family Lycaenidae, is distributed as scattered populations throughout the Great Basin and adjacent arid regions of western North America. In Nevada, it is represented with seven morphologically defined subspecies, four of which are recognized as “at risk” by the state’s Natural Heritage Program Office. Populations of E. pallescens are highly host-specific, with both adults and larvae closely tied to just one perennial buckwheat (Eriogonum) species at each locality where the butterfly occurs. One subspecies, the Sand Mountain blue (Euphilotes pallescens arenamontana), has been targeted for conservation due to the anthropogenic destruction of much of its sand dune habitat. While the Sand Mountain blue and its related subspecies are geographically isolated and morphologically distinct (though highly variable), no attempt had been made previously to explore patterns of genetic diversity among them. To explore these patterns, we sequenced one mitochondrial region (a portion of CO1) and two nuclear regions (ITS1 and EF1-alpha) from six of the seven subspecies (as well as from other Euphilotes species). The three genes were analyzed separately for phylogenetic structure, and with an analysis of molecular variance (AMOVA) for the mitochondrial region.
Results/Conclusions
Phylogenetic analyses resulted in phylogenetic trees that show little genetic distinction between the subspecies, but suggest a complex history for the species in Nevada, possibly including periods of extended isolation followed by hybridization among conspecific populations and other closely related Euphilotes species. AMOVA indicated a low level of genetic isolation among populations, consistent with either ongoing gene flow among some populations, or a recent, shared evolutionary history. This investigation can serve as a foundation for the future ecological and evolutionary studies of this complex species, which may be necessary to inform a targeted conservation strategy.
