Simulium doisaketense, Jitklang, Sanae, Kuvangkadilok, Chaliow, Baimai, Visut, Takaoka, Hiroyuki & Adler, Peter H., 2008

Jitklang, Sanae, Kuvangkadilok, Chaliow, Baimai, Visut, Takaoka, Hiroyuki & Adler, Peter H., 2008, Cytogenetics and morphotaxonomy of the Simulium (Gomphostilbia) ceylonicum species group (Diptera: Simuliidae) in Thailand, Zootaxa 1917, pp. 1-28 : 20-21

Simulium doisaketense n. sp.

(Figs. 6I, 7H, 9H, 11H)

Diagnosis: The larva can be distinguished from that of other cytoforms by the combination of distinct head spots, greenish transverse bands on abdominal segments I–IV, and postgenal cleft about 1.8–2.0 x as long as the postgenal bridge. The pupa cannot be distinguished from that of other cytoforms.

This species differs morphologically from S. asakoae as follows:

Female and male. Unknown. Pupa. Gill filaments ( Fig. 11 H) (3) + (1 + 2) + 2 from dorsal to ventral; terminal hooks each with crenulated outer margin; anterodorsal margin of cocoon somewhat produced anteriorly. Larva. Abdominal segments I–IV each with greenish transverse band.

Chromosomes. The faintly staining chromosomes of 31 larvae from 6 populations (sites 3, 15, 17, 22, 28, and 29) were analyzed. This species is characterized by fixed inversions IIS-8 (Fig. 4A), IIL-11 ( Fig. 11 A), and IIIL-complex 6 (Fig. 6I) and by five floating inversions (IIS-7, IIL-7, IIIL-6, IIIL-7, and IIIL-8; Figs. 4A, 5A, 6I). The centromere regions were not expanded.

Type specimens. Holotype: Pupa and cocoon (in ethanol vial). THAILAND, Chiang Mai Province, Ban Huai Mor, 19º02'N 99º20'E, 11.XI.2003, C. Kuvangkadilok and S. Jitklang. Paratypes: 2 pupae, 2 mature and 7 immature larvae (transferred from Carnoy’s fixative to 95% ethanol), same data as holotype.

Bionomics. The larvae and pupae of this species were collected from streams 1.5–3.8 m wide at altitudes from 300 to 850 m, with a substrate mostly of boulders, rarely small stones and sand ( Table 3 ). All samples came from streams in northern Thailand except one stream at Ban Passaduglang, Kanchanaburi, in central Thailand, where this species was collected with S. nr. asakoae 2. This species occurred with S. asakoae at site 28.

Etymology. The species name refers to the district, Doi Saket, in Chiang Mai Province where the species was collected.

Figures

FIGURE 11. Gill filaments of 10 cytoforms of the Simulium ceylonicum species group in Thailand. (A) S. asakoae, (B) S. curtatum n. sp., (C) S. nr. asakoae 2, (D) S. nr. asakoae 3, (E) S. nr. asakoae 4, (F) S. sheilae, (G) S. trangense n. sp., (H) S. doisaketense n. sp., (I) S. nr. sheilae 3, and (J) S. inthanonense. Scale bar = 0.1 mm.