however, it is possible that our sample also included members of
Simulium (Hellichiella)minus. These two species are indistinguishable in the immature stages, and they occur sympatrically in the Sierra Nevada of California, from
where some of the studied specimens were obtained. Accordingly, the high level of divergence exhibited by Simulium (Hellichiella)nebulosummight be the result of
a mixed sample. Mean intraspecific and interspecific divergence were 0.76% and 14.93%, respectively (species complexes not included; Fig. 2). At the generic level, average
DNA divergence varied across taxa, with a mean interspecific divergence value of 14.99% (minimum and maximum values were 2.83% and 20.02%, respectively; Table 3).