Nearctic–Palaearctic relationships of black flies (Diptera: Simuliidae): chromosomal and morphological evidence for the Prosimulium magnum species group in Japan

Abstract

The banding patterns of the polytene chromosomes of Prosimulium yezoense Shiraki from Japan are resolved relative to the standard map for the genus Prosimulium, revealing two unique fixed inversions and novel autosomal and sex-linked rearrangements. Diagnostic chromosomal and morphological criteria demonstrate that P. yezoense is a member of the Prosimulium magnum group. The species is transferred, with three additional species – P. apoina Ono, P. karibaense Ono, and P. sarurense Ono – from the Prosimulium hirtipes group to the P. magnum group, representing the first geographic record of the group outside North America. The P. magnum group is one of only a few insect taxa, and one of only two simuliid taxa, distributed exclusively in Japan and the Nearctic region.

Keywords:

• aquatic insects
• Prosimulium
• biogeography
• polytene chromosomes

Acknowledgements

This work was funded, in part, by National Science Foundation grant DEB-0933218. We thank Y. Otsuka and M. Fukuda (Oita University) for helping with the field collecting, and D. C. Currie (Royal Ontario Museum), J. W. McCreadie (University of South Alabama), and anonymous reviewers for comments on the manuscript. This is Technical Contribution No. 5937 of the Clemson University Experiment Station, and is based on work supported in part by NIFA/USDA, under project number SC-1700276.