The salivary gland chromosomes of the Himalayan black fly Simulium (Simulium) dentatum (Diptera: Simuliidae).

ABSTRACT

Proper identification of the black files is facilitated by chromosomal characteristics when morphotaxonomic parameters are Insufficient to distinguish a species. Using photo composites, we constructed and describe from the salivary glands of larvae a standard polytene chromosome map of a Himalayan black fly, Simulium (Simulium) dentatum, in the multistriatum group (Diptera Simuliidae). This species has three metacentric polytene chromosomes (n=3), with homologues more or less Intimately paired and having a prominent centromere. The largest chromosome (I) was 40.55% of total complementary length (TCL); chromosomes II and III were 30.14% and 29.31%, respectively. Chromosome I is characterized by the presence of a prominent nucleolar organizer at IS 19. Chromosome II is characterized by the presence of a Balbiani ring at MS 41B, followed by bulge and a Parabalbiani ring at IIL 64 B. Prominent homogeneously stained centromeres of chromosomes I, II, and III lie at the map positions L21A, L55, and L84, respectively.