Reproductive Status of Cytoforms in a Black Fly Complex in Montana

Abstract

We studied the reproductive status of cytospecies and cytotypes of the Simulium arcticum complex at four sites in Montana by comparing banding sequences of polytene chromosomes of the larval salivary glands to 1) identify cytospecies and cytotypes, 2) determine genotypes and frequencies of autosomal polymorphisms, and 3) assess the degree of reproductive isolation of taxa. We hypothesized that taxa within the complex that have large geographic distributions would be reproductively isolated in sympatry, while those that have very limited geographic distributions would not. Data from four separate collection sites support our hypothesis and possibly suggest a model for divergence within the group.