Simulium tani Takaoka and Davies, 1995

Tangkawanit, Ubon, Kuvangkadilok, Chaliow, Baimai, Visut & Adler, Peter H., 2009, Morphotaxonomy of the Simulium (Simulium) tuberosum species group (Diptera: Simuliidae) in Thailand, Zootaxa 2048, pp. 31-46 : 38

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.

Figures

FIGURE 3. Postgenal clefts of mature larvae of Simulium tuberosum group from Thailand. A, S. doipuiense cytoform A. B, S. doipuiense cytoform B. C, S. manooni. D, S. rufibasis. E, S. setsukoae. F, S. tani cytoform F. G, S. tani cytoform G. H, S. weji. I, S. yuphae. J, Unknown species 2. Scale bars = 0.1 mm.

FIGURE 5. Cephalic plates of pupae (female) of Simulium tani complex from Thailand. A, S. tani cytoform D. B, S. tani cytoform H. Insets show density of microtubercles. Scale bars = 0.1 mm.

FIGURE 7. Gill filaments of Simulium tuberosum group from Thailand. A, S. doipuiense cytoform A. B, S. manooni. C, S. rufibasis. D, S. setsukoae. E, S. tani cytoform F. F, S. tani cytoform H. G, S. weji. H, S. yuphae. Arrow indicates pit-like organ.

FIGURE 8. Pair of terminal spines (arrow) on pupa of a member of the Simulium tani complex from Thailand. Scale bar = 0.1 mm.

FIGURE 9. Median sclerites of males of Simulium tuberosum group from Thailand. A, S. doipuiense cytoform A. B, S. rufibasis. C, S. setsukoae. D, S. tani complex. E, S. weji. F, S. yuphae. Scale bars = 0.05 mm.