Stenopsyche siamensis Martynov 1931

Hoang, Duc Huy & Bae, Yeon Jae, 2007, Vietnamese species of Stenopsyche McLachlan (Trichoptera: Stenopsychidae), Zootaxa 1624, pp. 1-15 : 7-8

Stenopsyche siamensis Martynov 1931 ( Figs. 4 a–4h)

Stenopsyche siamensis Martynov 1931: 5 (male; Khaosam, Trang, Thailand); Ismail et al. 1993: 199 (male & female; Peninsular Malaysia); Ismail et al. 1996: 241 (larva; Peninsular Malaysia); Klaytong 2003: 41 (male; Thailand).

Male. Body 12 mm; forewings 14 mm; antennae 17 mm. Spur formula 0. 4. 4. The male adult was described by Martynov (1931), Ismail et al. (1993), and Klaytong (2003).

Female. Body 14–16 mm; forewings 16.5–17 mm; antennae 18–19 mm. Spur formula 2. 4. 4. The female adult was described by Ismail et al. (1993).

Larva. Body 30 mm, width 3 mm. Sclerites completely dark brown. Head 3.3 mm, width 1.2 mm. Pronotal median suture present. The larva was described by Ismail et al. (1996).

Diagnosis: The male adult of S. siamensis can be distinguished from other species of Stenopsyche by the shape of dorsal projections of segment X and short and forked superior arms ( Figs. 4 a–4c). The larva of S. siamensis can be distinguished by the completely blackish brown head ( Figs. 4 d–4f), relatively long and curved apical process of forecoxae ( Fig. 4 h), and moderately thickened median part of posterior prosternite ( Fig. 4 g). In case the larval head color is brown or light brown, the punctate pattern occurs ambiguously.

Material examined. VIETNAM. Nghe An Prov.: 3 larvae, Con Cuong, Khe Luong Creek, 2 i 2002, V.V. Nguyen. Quang Binh Prov.: 12 larvae, Son Trach, Phong Nha Cave, 15 viii 2001, V.V. Nguyen. Thua Thien–Hue Prov.: 8 larvae, Bach Ma National Park, Khe Boi, Khe Xu & Hydro-electric waterfall, 19 vi 2001, V.V. Nguyen. Da Nang City: 1 male, 4 females & 79 larvae, Ba Na–Nui Chua Reserve, An Loi Creek, alt. 200–300 m, 1 & 2 iv 2002, D.H. Hoang & V.V. Nguyen; 2 larvae, Son Tra Reserve, alt. 200 m, 4 iv 2002, D.H. Hoang & V.V. Nguyen. Lam Dong Prov.: 1 male & 16 larvae, Duc Trong, Tuyen Lam, Da Tangla Creek, alt. 1320 m, 26 iii 2002, D.H. Hoang & V.V. Nguyen; 19 larvae, Bao Loc, Da M’re Creek, alt. 300–430 m, 22 iii 2002, D.H. Hoang & V.V. Nguyen.

Distribution. Thailand, Malaysia, Central and Southern Vietnam (Nghe An Prov., Quang Binh Prov., Thua Thien–Hue Prov., Da Nang City, Lam Dong Prov.).

Remarks. This is a widespread species of Stenopsyche in mainland Southeast Asia. It has a large degree of morphological variations in the male adult genitalia ( Klaytong 2003). The Vietnamese larvae of S. siamensis have a median suture in the pronotum, while the Malaysian larvae lack it ( Ismail et al. 1996).

Figures

FIGURE 4. Stenopsyche siamensis Martynov. a – c: male genitalia. a: dorsal; b: lateral; c: ventral. d – h: full-grown larva. d: dorsal head; e: lateral head; f: ventral head; g: ventral prothorax; h: processes of right forecoxa.