Culex (Culiciomyia) sarpangensis Somboon, Namgay & Harbach, 2024

SOMBOON, PRADYA, SAINGAMSOOK, JASSADA, NAMGAY, RINZIN & HARBACH, RALPH E, 2024, Culex sarpangensis, a new species of the subgenus Culiciomyia Theobald of the genus Culex Linnaeus (Diptera: Culicidae) from Bhutan, Zootaxa 5543 (4), pp. 572-578 : 574-576

Culex (Culiciomyia) sarpangensis Somboon, Namgay & Harbach , sp. nov.

Fourth-instar larva (based on three specimens) ( Fig. 1a‒d ). Small, pale yellowish. Chaetotaxy in Table 1 . Head ( Fig. 1a ): Width 0.74‒0.78 mm (mean 0.75 mm), length 0.59‒0.62 mm (mean 0.60 mm), more yellow than thorax, abdomen and siphon, integument smooth. Dorsomentum somewhat triangular, with 27‒31 minute teeth ( Fig. 1b ). Seta 1-C fine, slightly curved mesally; setae 5,6-C long, with 3 aciculate branches; seta 7-C long, with 4 or 5 aciculate branches; setae 8‒10-C usually with 2 simple branches; setae 11,12-C with 3‒6 simple branches; seta 13- C with 3‒5(3) aciculate branches. Antenna: 0.5 length of head width, slightly bent laterad, with many long spicules on dorsal surface, relatively strong spicules from base to seta 1-A, few small or minute spicules beyond seta 1-A, ventral surface with sparse minute spicules. Seta 1-A with 15–20 long aciculate branches, inserted about 0.66 from base; seta 2,3-A subapical. Thorax: Integument without covering of spicules. Setae 1,2,3-P single, long, aciculate, seta 3-P distinctly weaker and about 0.5 length of setae 1,2-P; setae 4,5,6,8,12-P single, strong, aciculate; seta 7-P double, aciculate; setae 9,10-P single, weak, simple; seta 14-P single; seta 1-M with 2–4(3) simple branches, much longer than seta 2-M but shorter than seta 3-M; seta 3-M single, simple; seta 4-M single or double; setae 5,6,7,10,12- M single, strong, aciculate; seta 9-M with 3 strong aciculate branches; setae 1,2,3,4,6-T simple, weak, with 1 or more branches; setae 7,9-T with 3–5 strong aciculate branches; seta 10-T single, strong, aciculate; seta 13-T with 4 simple branches. Abdomen: Seta 1-I,II,III,VI usually with 1 or 2 weak branches, 1-IV,V,VII single, noticeably long, strong, aciculate, 1-VIII with 3 aciculate branches; seta 6-I,II with 2 strong aciculate branches, 6-III,IV,V,VI single, strong, aciculate; seta 7-I single, strong, aciculate, 7-II,III,IV,V weak, with 3–6 simple branches, 7-VI,VII single, weak, simple; seta 13-I single, small, 13-II small, with 6–10(6) branches, 13-III,IV,V,VII with 2 or 3 branches, 13- VI weak, with 9–14(12) branches. Comb with 34–52 scales, scales rounded and evenly spiculate apically, lateral spicules present on some scales. Saddle incomplete, lightly pigmented, surface with rows of minute spicules and posterior margin with strong and weaker spicules. Seta 1-X single, simple, as long as saddle, inserted near edge of saddle; seta 2,3-X single, simple; seta 4-X (ventral brush) with 4 pairs of setae (setae 4a–4d), 3 on grid, 4a inserted anterior to grid, small, single, about 0.33 length of 4b, 4b single or double, about 0.5 length of 4c, 4c about 0.75 length of 4d, both setae with 2, 3 or 4 branches, branches of 4c and 4d arise a noticeable distance from the base of the stem. Anal papillae lanceolate, 2.5–3.0 length of saddle. Siphon: Length 1.37‒1.47 mm (mean 1.42 mm), same colour as abdomen, moderately long, index 6.08‒6.90, wide at base, distal 0.5 evenly narrower; acus present; pecten with 7–9(9) spines, each with fine proximal denticles; seta 1-S weak, inserted distal to pecten, shorter than width of siphon at point of attachment, comprised of 3 pairs of ventrolateral setae, 2 proximal pairs single, distal pair widely spaced from proximal pairs, single or double; setae 2,6,7,8,9-S single, weak.

Etymology.The specific name, sarpangensis , is an adjective formed by adding - ensis (L. masculine and feminine suffix denoting place, locality, country) to the name of the Sarpang District, the type locality in Bhutan, to produce a Latinized name meaning “from Sarpang”.

Type series. Three larvae. Holotype (CxSp2): Bhutan, Sarpang District, Umling Gewog (26.852722 N, 90.533333 E, elevation 220 m), found in stream margin, 31 October 2017, collector Pradya Somboon. Paratypes: Same data as holotype. The holotype and paratype (CxSp1), mounted on separate microscope slides, are deposited in the collection of the Entomology Section, Queen Sirikit Botanic Garden, Chiang Mai, Thailand .

Bionomics. Larvae of Cx. sarpangensis were collected from the margin of a slow running stream, about 30 cm deep and partially shaded. Associated species included Cx. nigropunctatus and Anopheles peditaeniatus ( Leicester, 1908). The adults and pupa are unknown.

Distribution. This species is only known at present from Umling Gewog, Sarpang District, Bhutan.

Figures

FIGURE 1. a–d, Fourth-instar larva of Cx. sarpangensis. (a) Head, dorsal (left) and ventral (right) aspects of left side, (b) dorsomentum, (c) thorax and abdominal segments I–VI, dorsal (left) and ventral (right) aspects of left side, and (d) abdominal segments VII, VIII, X and siphon, left side. A, antenna; APP, anal papillae; C, cranium; Dm, dorsomentum; P, prothorax; Pt, pecten; M, mesothorax; S, siphon; Sa, saddle; T, metathorax; I–VIII,X, abdominal segments I–VIII and X; 1–15, setal numbers for specified areas, e.g. seta 3-P and 4a.