Stenopsyche drakon Weaver 1987

Nozaki, Takao, Saito, Rie, Nishimura, Noboru & Tojo, Koji, 2016, Larvae and females of two Stenopsyche species in Taiwan with redescription of the male of S. formosana (Insecta: Trichoptera), Zootaxa 4121 (4), pp. 485-494 : 490-492

Stenopsyche drakon Weaver 1987

( Fig. 5 )

Stenopsyche drakon Weaver 1987 , 165–167, male, Taiwan; Malicky 2014, 1624, Taiwan; Nishimura et al. 2015, 78, 81, Taiwan.

Adult. Forewings of male each 19 mm long (n=2), of female 20–22 (n=3), brown with many pale spots, irregularly reticulated; hind wings white or slightly pale brown, subhyaline. Antennae about 1.5 times as long as forewings in male, slightly longer than forewings in female. Legs yellowish brown, middle legs with dark markings on tibiae and 1st to 2nd segments of tarsi, markings on foretibiae indistinct. Tibial spurs 3, 4, 4.

Female genitalia. Segment IX rectangular in lateral aspect, with long apodemal extension on each anteroventral corner; in dorsal view mostly sclerotized but separated by membrane along dorsal midline, posterodorsal area membranous, each sclerotized plate with transverse row of setae about 1/3rd distance from anterior margin, 1 pair of setae near posterior margin. Segment X (segment XI of Schmid 1969) membranous dorsally, with pair of setose longitudinal sclerites dorsolaterally; ventral setose area weakly sclerotized with apicomesal incision; apex divided into pair of distal lobes, each with cercus. Vulvar scale large; each side sclerotized, subrectangular in lateral aspect, with long stout setae apicolaterally; posterior margin sinuous in ventral aspect, membranous mesally. Vaginal chamber sclerotized, projecting anterodorsad in lateral aspect; ventral part pentagonal posteriorly in ventral aspect, tongue-shaped anteriorly in lateral and ventral aspects.

Final instar larva. Length up to 35 mm. Head 3.6–3.8 mm long (n=2); anterior part about 1.6 mm wide (eye level), posterior widest part about 1.8 mm; ground color yellowish brown, with many dark distinct spots and markings, frontoclypeus without dark longitudinal band on mid-line; with irregular dark spots and two small dots anteriorly, big dark spot and two transverse stripes on middle and posterior position; other parts of head with various dark spots; primary setae 1, 4, 10, 11, 13 not dark pigmented; setae 8, 15, 18 located ventrally; setae 18 not bifurcated, about 0.25 mm, located near postoccipital ridge, each surrounded by rugged, triangular area. Pronotum 2.4–2.6 mm long, about 2.2 mm wide, ground color yellowish brown, with many small dark spots except for anterodorsal area, posterior margin black. Forecoxae pentagonal in mesal view, each apicodorsal process very long, horn-like, directed anterad, curved slightly ventrad; each basodorsal process about 1/4 as long as apicodorsal process, close to apicodorsal process, with long dorsal seta near apex; each central process on mesal face with short stout seta dorsally in middle.

Specimens examined. [ TAIWAN] Beigang River, Huisun Forest Area, Ren’ai Xiang, Nantou, 24°4.992’N, 121°0.651’E, alt. 490 m, 3.iii.2015, N. Nishimura, 1 male, 2 larvae (SU); same locality, 3.iii.2015, L.P. Hsu, 2 females (1 female: SU, 1 female: TN); Meiyuan River, Ren'ai Xiang, Nantou, 24°5.09’N, 120°57.22’E, alt. 504 m, 4.iii.2015, N. Nishimura, 1 male, 1 female (1 male: SU, 1 female: TN).

Remarks. The female of this species has dorsum IX mostly sclerotized but separated by membrane along the dorsal mid-line. A continental species, S. huangshanensis Xu et al. 2015 , also has this character ( Xu et al. 2015), but S. huangshanensis can be distinguishable from the former by the lack of a row of setae on each sclerotized plate. The larva of this species can be easily distinguished from known Stenopsyche larvae by the combination of following characteristics: Large distinct markings of the head but lacking dark longitudinal band on mid-line of frontoclypeus, unbifurcated no. 18 setae of the head, and long apicodorsal process of each forecoxa.

Figures

FIGURE 5. Female and larva of Stenopsyche drakon. A – C, female genitalia: A, left lateral; B, ventral; C, dorsal. D – G, larva: D, head, dorsal; E, head, ventral; F, prothorax, dorsal; G, mesal surface of right forecoxa, left lateral.