Genetic diversity and population structure in the threatened Oregon silverspot butterfly (Speyeria zerene hippolyta) in western Oregon and northwestern California— Implications for future translocations and the establishment of new populations

Open-File Report 2016-1162
Prepared in cooperation with the U.S. Fish and Wildlife Service
By: , and 

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Executive Summary

We present results of population genetic analyses performed on Oregon silverspot butterflies (OSB; Speyeria zerene hippolyta) in western Oregon and northwestern California. We used DNA sequences from a 561-base pair region of the mitochondrial cytochrome oxidase subunit I (COI) gene for a dataset comprised of 112 S. z. hippolyta and 32 S. z. gloriosa individuals collected at 9 locations in western Oregon and northwestern California. The most pertinent findings thus far are summarized as follows:

  • Among OSB populations, genetic diversity is lowest at Mount Hebo and highest at Rock Creek and Bray Point. Of the 32 haplotypes detected in OSB, only 2 were shared among populations (1 shared by Mount Hebo, Cascade Head, Bray Point, and Rock Creek, and 1 shared by Rock Creek and Lake Earl). The remaining 30 haplotypes were identified in individual populations, highlighting the strong differentiation among sites. It is unclear if the shared haplotypes represent widespread, naturally occurring genetic variation or if allele sharing among populations is due to translocation history.
  • Using full siblings of individuals that were released at Rock Creek and Bray Point in 2012 as comparison standards, the analyses suggest that 54 percent of the sampled individuals from Bray Point were naturally recruited into the population and were not originating from the 2012 release of captive reared individuals. Likewise, 33 percent of the analyzed individuals from Rock Creek were naturally recruited. Both of these estimates may be underestimates if the shared alleles that we identified among populations are naturally occurring and not a product of the 2012 translocations.
  • The results suggest that there are about 12–13 COI haplotypes in the Mount Hebo population. The U.S. Fish and Wildlife Service anticipates using Mount Hebo as the source of individuals when establishing new populations in the future. Nonlinear regression models based on a series of rarefaction analyses suggest that progeny from 12, 37, 109, and 326 female individuals would be required to respectively capture 25, 50, 75, and 90 percent of the allelic diversity from Mount Hebo.
  • Phylogenetic analyses identified two different haplotype groups, but the two groups did not correspond to the different subspecies used in the analysis. One group included 22 S. z. hippolyta haplotypes and 7 haplotypes identified in S. z. gloriosa. The second group included eight haplotypes from S. z. hippolyta, three haplotypes from S. z. gloriosa, and one haplotype that was detected in both subspecies.

Suggested Citation

Miller, M.P., Mullins, T.D., and Haig, S.M., 2016, Genetic diversity and population structure in the threatened Oregon silverspot butterfly (Speyeria zerene hippolyta) in western Oregon and northwestern California—Implications for future translocations and the establishment of new populations: U.S. Geological Survey Open-File Report 2016-1162, 23 p., http://dx.doi.org/10.3133/ofr20161162.

ISSN: 2331-1258 (online)

Study Area

Table of Contents

  • Executive Summary
  • Introduction
  • Methods
  • Results
  • Discussion
  • Acknowledgments
  • Referenced Cited
  • Appendix1. Sample Information for Oregon Silverspot Butterfly Specimens Included in This Analysis
  • Appendix 2. Haplotype Frequencies Among Populations of Oregon SilverSpot Butterflies (Speyeria zerene hippolyta) and S. z. gloriosa

Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Genetic diversity and population structure in the threatened Oregon silverspot butterfly (Speyeria zerene hippolyta) in western Oregon and northwestern California— Implications for future translocations and the establishment of new populations
Series title Open-File Report
Series number 2016-1162
DOI 10.3133/ofr20161162
Year Published 2016
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Forest and Rangeland Ecosystem Science Center
Description Report: iv, 23 p.; Appendix
Country United States
State California, Oregon
Online Only (Y/N) Y
Additional Online Files (Y/N) Y