Hydropsyche xenga Oláh & Johanson, 2008

Oláh, J. & Johanson, K. A., 2008, Generic review of Hydropsychinae, with description of Schmidopsyche, new genus, 3 new genus clusters, 8 new species groups, 4 new species clades, 12 new species clusters and 62 new species from the Oriental and Afrotropical regions (Trichoptera: Hydropsychidae), Zootaxa 1802, pp. 1-248 : 152-153

Hydropsyche xenga Oláh & Johanson , new species

Fig. 261–265

This species is similar to H. serpentina Schmid from Hunan in China. Both species have apical lobe of phallotheca with 3 holes with membranous endothecal processes. Hydropsyche xenga differs significantly from H. serpentina in having the dorsolateral membranous endothecal process directed posterodorsad, with very short, apical spine; the apicoventral setose processes of segment X are directed ventrad, not posterad; and the harpagones are spatulate in ventral view.

Male. Body and wings ochraceous with light pubescence. Forewing membranes scarcely light-spotted. Sternite V with processes half as long as segment. Maxillary palp formula I-(III, IV)-II-V, segment V as long as sum of segments I–IV. Head dorsum light, almost yellow, with 9 warts of same light colour. Swollen setal wart present on proepisternum. Pretarsal claws asymmetrical, laterally flanked by setal bundle; bundles present only on forelegs. Spur formula 244. Protibiae with posteroapical spur almost equal to anteroapical spur.

Wings. Venation typical for the genus. Forewing crossveins m-cu and cu separate. Sc and R, and Cu2 and A separate before costa. Hind wing Sc and R meeting before costa about at crossvein r. Stem of M and Cu1 running closely. Median cell closed. Fork 1 present. Forewing length 6.5 mm, hind wing length 5.0 mm.

Male genitalia. Abdominal segment IX fused annularly, short ( Fig. 261). Median keel short, very wide ( Fig. 262), with granulose dorsal and lateral surfaces; anterior margin arciform, gradually sloping on dorsum, abruptly deepen at ventrum ( Fig. 261); ventrum very short; dorsum 2 times longer than ventrum ( Fig. 261). Antecosta well developed, widens before margin. External groove of antecostal suture present. Apical lobe on posterolateral margins short, straight cut ( Fig. 261). Posterior spine rows intermittent, present on median keel slope and apical lobes, absent between. Depression between segments IX and X completely filled, forming almost straight horizontal line with apicodorsal setose lobes. Body of segment X quadrangular ( Fig. 261, 262); dorsum short, ventrum longer ( Fig. 261). Lateral setose areas (preanal appendages) in deep, ventral position forming compact, less pigmented, ovoid, setose areas, and scattered groups of setae posterior of light setose window; diffuse group of setae not shifted to distal margin of segment X. Apicoventral setose lobes arising from middle of segment X, directed posteroventrad, shorter than body of segment X; broad, robust, parallel-sided ( Fig. 261). Dorsal interlobular gap long, narrow surrounded by apicoventral lobes and sharply triangular anterior basis. Apicodorsal setose lobes located apically on dorsum, forming pair of circular setose ridges of double crests fused with smooth central depression; smooth cavity on anterolateral area of segment X very deep. Rim of cavity anteriorly surrounded by pair of transverse sutures or posterior rim of segment IX, and by pair of short, longitudinal sutures located under smooth cavity. Coxopodites short, robust, each with slightly sinuous dorsal margin and nearly straight ventral margin ( Fig. 261), straight in ventral view ( Fig. 263). Harpagones slightly curving dorsad in lateral view ( Fig. 261), tapering apically in lateral view ( Fig. 261); broadly spatulate in ventral view ( Fig. 263). Phallic apparatus double sinuate, forming long tube with nearly same diameter along bend ( Fig. 264); distally narrow before heavily pigmented, double rounded, exposed phallotremal sclerites; apical lobe narrow in lateral view ( Fig. 264). Phallotremal sclerites with tube constricted in ventral view ( Fig. 265). Sclerotized apical phallothecal lobe with 3 holes hiding eversible membranes with cluster; lateral membranous lobes with small apical spines; central membranous lobe without spines. In ventral view, apical lobe of phallotheca widening strongly into rectangular lobes after constriction ( Fig. 265). Pair of dorsal, erect, posterad curving dorsolateral membranous endothecal lobes present, with small, mesally curving spine arising near basis of phallotremal sclerites. Endophallus filling almost entire hor-

izontal section of phallotheca anterad of phallotremal sclerites; narrowing suddenly before gonopore.

Holotype male: VIETNAM: Bac Thai Province , Quang Chu, 14–15.v.1987, light [J. Oláh] ( OPC, in alcohol).

Paratypes: same data as holotype — 1male ( OPC, in alcohol) .

Distribution. Vietnam.

Etymology. xenga , from “cai xeng”, meaning shovel in Vietnamese, referring to the unusually spatulate harpago.