Setodes scutatus, Yang & Hu & Morse, 2020

Yang, Lian-Fang, Hu, Ben-Jin & Morse, John C., 2020, Interesting new Chinese species of Leptoceridae and Odontoceridae (Insecta: Trichoptera) from several recent collecting efforts, Zootaxa 4732 (1), pp. 138-160 : 153

Setodes scutatus n. sp. Yang & Morse

( Fig. 9 )

Diagnosis. This species belongs to the Setodes argentiferus Group ( Schmid, 1987), and is most similar to Setodes trilobatus Yang & Morse 1989 from northern China (Shaan-xi) in the following characters: 1) abdominal tergum X is broad, roof-like, its apicomesal portion is distinctively protruded backward beyond two apicolateral ends; 2) each inferior appendage is tri-branched; 3) the phallicata of the phallus is dilated subapically with a beak-like tip. It can be differentiated easily from S. trilobatus in the following characters: 1) the lower branch of each inferior appendage is long, blade like, with its length 1.2 times the length of the ventral margin of segment IX, and with a triangular projection on its dorsal margin in lateral view (the lower branch of each inferior appendage is a short oval lobe, with its length 2/3 the length of the ventral margin of segment IX in S. trilobatus ); 2) the parameres are each branched subapically into two decurved hooks (not branched subapically in S. trilobatus ); 3) the mesal branch of each inferior appendage is stout, with its apex strongly produced mesad into a triangular process and with the mesal end acute in caudal view, (the mesal branch is a narrow band, its apex with the mesal process slender in caudal view in S. trilobatus ); 4) the paired basomedian lobes of tergum X are about as broad as the preanal appendages and with truncate apices in dorsal view (much smaller and subtriangular in S. trilobatus ); and 5) the phallus has a narrow crescent phallobase (the phallobase is semicircular in S. trilobatus ).

Adult. Length of each male forewing 6.5–7.0 mm (n = 5). Specimen in alcohol generally pale yellow, forewings without evidence of golden spots or striae, covered with concolorous fine hair. Wing venation typical for genus, cell R3 (between veins R3 and R 4+5) almost as long as fork of MA and MP (between veins M1+2 and M3+4), tips of fore- and hind wings acute ( Figs. 9F, 9H ).

Male genitalia. Segment IX longitudinally short dorsally, forming narrow transverse band ( Fig. 9A ). Preanal appendages large, setose mounds, positioned beside basomedian lobes of tergum X in dorsal view ( Fig. 9B ). Tergum X long and broad, roof-like with prominent median ridge ( Fig. 9A ); in dorsal view 1.5 times as long as wide, basal median lobes each with truncate apex and about as broad as preanal appendage ( Fig. 9B ), apicomesal end distinctively protruding backward beyond two apicolateral ends, forming trilobed apex ( Fig. 9B ). Inferior appendages each trifurcate, lower branch of appendage elongate blade-like, 1.2 times as long as ventral margin of segment IX and with triangular projection on midlength of dorsal margin in lateral view ( Fig. 9A lower arrow); mesal branch short, 1/2 as long as upper branch of inferior appendage, with apex blunt in lateral view but in caudal or dorsal views strongly produced mesad into triangular process with acute mesal end ( Figs. 9A middle arrow, 9A-a); small, setose papilla visible at base in caudal view ( Fig. 9 C-a arrow); upper branch slender and sinuate, 2/3 as long as lower branch of inferior appendage, with apex bearing two long setae ( Figs. 9A upper arrow, 9C-a.). Phallus with narrow crescentic phallobase; pair of parameres stout, originating above phallobase, curved caudad then sloping caudoventrad, each branched subapically into two decurved hooks with inner hook nearly transparent; phallicata strongly arched, slender, parallel sided in basal half in lateral view, with distal half expanded dorsolaterally into two broad subapical lobes, with abruptly narrowed beak-like apex directed downward ( Fig. 9D ).

Holotype male. PR CHINA: Shan-xi Province : Yi-cheng County, Xi-yan-zhen Town , Da-he Villege , Sangou-he Stream, N35.451, E111.932, alt. 996 m, water temperature 16°C, 15 Jun 2013, Coll. Sun Ch-h. and Xu Ji-h.

Paratypes. Same data as holotype, 4 males.

Etymology. Latin, scutatus , adjective, meaning shield-shaped, with reference to the broad, plate-like tergum X.

Distribution. East Palearctic Biogeographic Region, Northeast China.

Figures

FIGURE 9. Setodes scutatus Yang & Morse, sp. n., male. 9A–9D, genitalia: 9A, left lateral; 9A-a, apex of mesal branch of left inferior appendage, dorsal; 9B, dorsal; 9C, ventral; 9C-a, left inferior appendage, caudal; 9D, phallus, left lateral. 9F, Right forewing, dorsal. 9H, Right hind wing, dorsal.