Morphotaxonomy of the Simulium (Simulium) tuberosum species group (Diptera: Simuliidae) in Thailand Author Tangkawanit, Ubon Author Kuvangkadilok, Chaliow Author Baimai, Visut Author Adler, Peter H. text Zootaxa 2009 2048 31 46 journal article 10.5281/zenodo.186496 a6aa7826-075e-4c7e-a095-ea3a3cd23017 1175-5326 186496 Simulium tani Takaoka and Davies, 1995 (complex) The members of the S. tani complex can be distinguished from other species of the S. tuberosum group by the roundish margins of the postgenal cleft ( Fig. 3 F, G) and ventral tubercles of the larva, short terminal spines ( Fig. 8 ) of the pupa, absence of a pair of clustered hairs on sternite VII in the female, and a narrow median sclerite in the male ( Fig. 9 D). Structural variation within each of the nine cytoforms is typically as great as it is among cytoforms ( Table 1 ), with one exception. The pupa of cytoform H has a lower density of cephalic microtubercles ( Fig 5 B) and a longer ventralmost gill stalk ( Fig. 7 F) than do other cytoforms in the complex. Variation in meristic characters among cytoforms, such as the number of primary rays in the labral fan, probably is related to habitat ( Zhang & Malmqvist 1997 ). Some of the cytoforms of the S. tani complex might prove to be valid species. Cytoform B or D, because of geographical location, probably represents true S. tani , which was described from Malaya .