The Salivary Gland Chromosomes of the Himalayan Black FlySimulium(Simulium)dentatum(Diptera: Simuliidae)

Proper identification of the black flies 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 IIS 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.