Strauzia longipennis (Wiedemann) is a notoriously variable species. Seven varieties were once recognized, all but three considered as synonyms by some authors. Other authors, based on host records, elevated two sympatric varieties to full species status. Such taxonomic instability, particularly when associated with variable patterns of host use, suggests that S. longipennis may represent a dynamic complex of host-associated populations in the process of divergence. To detect evidence of genetic differentiation within populations of S. longipennis, we sequenced a fragment of cytochrome oxidase subunit I of mitochondrial DNA of S. longipennis from two sites in eastern Iowa. At each site, we found two genetically and morphologically distinct sympatric populations: one corresponds to descriptions of S. longipennis var. typica (Loew); the other corresponds to S. longipennis var. vittigera (Loew). Our observations suggest that some gene flow occurs between these divergent sympatric populations, which might represent host-races
or incipient host-races.
John R. Gammons, ’08 Beaverton, OR
Majors: Biochemistry and Molecular Biology, Environmental Studies
Heather J. Axen, ‘06
Jessica Harrison, ‘05
Marty Condon, Ph.D.
Sponsor: Marty Condon