Homosequential species 2a and 2b within the Prosimulium onychodactylum complex (Diptera): temporal heterogeneity, linkage disequilibrium, and Wahlund effect

• Published in: Canadian Journal of Zoology
• Main Author: Henderson, Christine A. P.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1986
• Subjects: Alaska; Yukon
• Online Access: http://dx.doi.org/10.1139/z86-129; http://www.nrcresearchpress.com/doi/pdf/10.1139/z86-129

Prosimulium onychodactylum 2 within the P. onychodactylum complex comprises two homosequential forms designated P. onychodactylum 2a and P. onychodactylum 2b (L. J. Newman. 1983. Can. J. Zool. 61: 2816–2835). The present paper presents evidence that forms 2a and 2b are reproductively isolated by demonstrating the existence of temporal heterogeneity, inversion linkage disequilibrium, and heterozygote deficiencies in larval samples from five sites where both forms occur. On the basis of differential frequencies of shared inversion polymorphisms, these samples could be partitioned into subsamples of 2a and 2b which were in Hardy–Weinberg equilibrium and exhibited random association of inversions. Form 2a consistently developed first and is the more widespread with samples from Alaska, the Yukon, British Columbia, Alberta, Washington, Idaho, Montana, Wyoming, and Colorado. Form 2b is restricted to the provinces and states south of Alaska and the Yukon Territory.