Hydromanicus fallax Mey

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 : 28-29

Hydromanicus fallax Mey

Fig. 32–33

Hydromanicus fallax Mey, 1996b: 60 .

Type locality. Vietnam .

New Record: VIETNAM: Bach Thai Province , Quang Chu, 24–25.v.1987 [J. Oláh] - 1 male, 1 female ( OPC, alcohol) .

Remarks. The only previously described female in the genus Hydromanicus was that of H. flavoguttatus Albarda described by Neboiss (1996). One female was captured in net by János Oláh along a second order stream near Quang Chu village in Vietnam in 1987, and a male was captured at the same spot 3 hours later when slowly returning and collecting carefully downstream the site. The species was described as H. fallax by Mey (1996). Here we describe the female.

Female ( Fig. 32–33). Body and wings as in male: brown with chestnut brown forewing membranes having light, rounded spots, mostly along costal, subcostal, radial and apical cells; longitudinal veins darker brown. Venation typical for the genus; however, forewing Cu2 and A1 are separate at posterior wing margin; hind wing Sc and R tangential at crossvein s. Forewing length 12.0 mm, hind wing length 9.0 mm. Maxillary palp formula I-(II,III)-IV-V. Proepisterna without setal warts. Precoxale (proepisternum) each with setal wart, or slightly elevated setal surface. Legs all with symmetrical claws (asymmetrical and laterally flanked by setal bundle in male legs). Vertex brown with 7 large, brown setal warts.

Female genitalia. Abdomen tapering slightly more posterad in lateral than in dorsal and ventral view; sagittally narrowing posterad. Tergum VIII quadrangular, narrowing apicad, with ventrocaudal, quadrate lobe ( Fig. 32); wide, shallow, sinuate, mesal dorsocaudal incision present, visible in dorsal view. Tergal surface bare ( Fig. 32); produced posterad, provided by tiny, closely-set microtrichiae; devoid of setae, except ventrocaudal lobes being covered by short, mesad curving setae. Pleurosternum, or posterolateral apodemes, narrow, parallel-sided, fusing with dorsal margin of sternum VIII; separated by well-developed sutures; surface weakly sclerotized; bare, except near distal margin; posterior margin protruding posterad, enforced by sclerotization and dorsad oriented longitudinal sutures along dorsal margins of sternum VIII. Sternum VIII quadrangular ( Fig. 32); with freely flanking or lapping ventrocaudal lobe-like corners; ventral plate ( sensu Nielsen 1980 ) or lateral plate ( sensu Denning 1943 ) formed by deep, wide, V-shaped incision ( Fig. 33); lobe-like corners with long setae flanking membranous, fused sternal portion of segment IX. Ventrocaudal lobes strongly setose. Besides long setae densely packed on ventrocaudal lobes, posterior half of sternum VIII scarcely covered by short setae; basal half without setae. Tergum IX vertically elongate in lateral view ( Fig. 32), directed obliquely to main axis of abdomen; broadening ventrally together with lateral lobe on ventrodistal corners of segment. Narrow antecosta present on anterior margins, with well developed acrotergite on dorsum; dorsal margin rounded in lateral and dorsal view, with group of 4–5 large, long closely set setae being almost brushlike on both sides of dorsocaudal margins. Sclerotized ridge running along anterior margins of tergum IX from acrotergite and clasper receptacle, down to anteroventral corner. Sclerotized ridge delineating shallow, flat, wide, indiscernibly depressed distal cavity of clasper groove, forming clasper area enlarged into wide distal depression of tergum IX. Clasper area ( Fig. 32) limited anteriorly by ridge on anterior margins, ventrally by elevated lateral lobes, and dorsally by dorsal rims housing clasper receptacles; elevated ventral part produced into developed lateral lobe ( sensu Denning 1943 ), or tongue-like lamellae ( sensu Nielsen 1980 ); surface covered by long setae. Clasper receptacle clearly helicoid ( Fig. 32). Distinctly marked sutures delineating less pigmented, short, tergum X along distal margin of tergite IX. Tergite X represents body of upper lip of atrium ( sensu Nielsen 1980 ), composed of pair of foliate, flat, lobes covered with short setae. Lobes each nested in rather large wart-like alveoli and tridactylate short lobes; dorsal lobe largest, with nearly truncate apex. Mid process, cercus ( sensu Nielsen 1980 ), digitate, slender, armed with 2 apical setae; dorsal and ventral processes blunt, with dense covering of tiny, peg-like setae on dome-like alveolar membranes in deep alveoli. Upper half of segment X with pair of unique, foliose lobes, not seen in other hydropsychid species. Sclerotized setose and foliate, small, flat lobe concealed basoventrally, partly covered by or underneath foliate, principal setose lobe of tergite X. This may represent rudimentary sternal lobes, or lateral tergal plate ( sensu Denning 1943 ). Lobes connected by smooth, membranous, triangular, median structures dorsally surrounding anovaginal openings; connected to lower lip at basis. Lower lip of atrium ( sensu Nielsen 1980 ), or vulvar scale ( sensu Schmid 1998 ) distended, bag-like. Vaginal apparatus in cleared abdomen membranous, except slightly sclerotized on sinuate, thin, part connecting lower lip to sclerotized tergum of segment IX; pair of slightly sclerotized plates present on dorsum of lower lip. Vaginal apparatus membranous in cleared abdomen, ending in laterally bilobed and ventrally trilobed proximal structure.

Remarks: This species varies in the length ratio of the maxillary palp segments. The female has symmetrical claws on all legs, while the male claws of all legs are asymmetrical and laterally flanked by a setal bundle.