Mean intraspecific
genetic divergence for the 58 evaluated morphologically
distinct species (i.e. members of species complexes not
included) was 0.76%. The maximum intraspecific divergence value (3.84%, mean = 1.03%) was observed in Simulium
(Simulium) rostratum, followed by Simulium (Nevermannia)
silvestre(3.51%, mean = 1.45%) and Prosimulium travisi
(3.36%, mean = 1.76%; Table 2). Higher levels of divergence
were found among members of cytologically defined
sibling complexes: Helodon (Helodon) onychodactyluscomplex
(max. 4.91%), Stegopterna mutatacomplex (max. 5.47%),
Simulium (Simulium) arcticumcomplex (max. 6.5%), Simulium
(Simulium)tuberosumcomplex (max. 5.44%) and Simulium
(Simulium)venustumcomplex (max. 5.31%; Table 2).
Putative species complexes also exhibited higher levels of
intraspecific divergence as in Simulium (Nevermannia)craigi
(max. 4.93%), Simulium(Nevermannia) quebecense(max.
5.79%) and Simulium (Simulium)murmanum(max. 4.58%).
Along similar lines, specimens identified as Simulium
(Hellichiella) nebulosumalso exhibit a high intraspecific
genetic divergence (max. 4.58%; Table 1