A cytological description of sibling species of Simulium venustum and S. verecundum with standard maps for the subgenus Simulium Davies (Diptera)

The paper proposes standard polytene chromosome maps for species groups in the subgenus Simulium. In the S. venustum/verecundum complex we distinguish by their chromosomes a minimum of seven sibling species designated by their IIS sequences, as follows: EFG/C (S. truncatum?) holarctic; EFG, Germany; CC (S. venustum?) North America (with probably CC 1 a separate sibling); A/C venustum, New Hampshire (with AC(gB) venustum Newfoundland probably distinct); CC 2 Ontario, Newfoundland; AA verecundum Newfoundland (with possibly A/C verecundum, Ontario distinct); and ACD (S. verecundum? = sublacustre) holarctic. Three of these taxa (EFG/C, ACD, and CC) were probably recognized by taxonomists, though the circumpolar distribution of the first two was not reliably recorded. The remaining species were not previously resolved. The chromosomal characteristics of all species are described and notes are given on available details of their biology and distribution. Some broad aspects of the relationship between cytological and taxonomic methodology in the group are discussed.