Setodes charax Yang & 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 : 151-153

Setodes charax Yang & Morse , n. sp.

( Fig. 8 )

Diagnosis. This new species belongs to Setodes dhanavriddha Group ( Schmid 1987), to which two additional species have been included: St. laertes Malicky & Chantaramongkol 2006 from Nepal and St. lailaps Malicky & Chantaramongkol 2006 from Thailand. The male genitalia of our new species have the form of those of St. antardhana Schmid 1987 , St. gherni Schmid 1987 , and St. divyarupa Schmid 1987 from India in the following characters: 1) The long lateral branches of segment X are positioned at 1/4 distance below the dorsal margin of segment IX, such that the dorsum of IX seems highly elevated in lateral view; 2) the lateral branches of X are serrate subapically and are usually fringed with long hair; and 3) the phallic parameres are very long and slender, arched parallel to the phallicata. However, the male genitalia of St. charax differ from those of these three species in the following characters: 1) The lateral branches of tergum X each is forked apically in lateral or dorsal views (not branched at the apex in St. antardhana and St. gherni , with the apex branched into three stout teeth in St. divyarupa ); 2) the phallicata is slen- der, trough-shaped, and the dorsal ridges are not expanded laterally for reception of the parameres (the dorsal ridges are expanded for reception of the parameres in the above three species); 3) the parameres are very long and slender, each deeply divided at 1/4 length into two subparallel branches (the parameres are not divided in St. antardhana , St. gherni , and St. divyarupa ).

Adult. Length of each male forewing 6.0– 6.5 mm (n = 2). Specimens in alcohol generally pale, forewings pale brown, covered with concolorous fine hair. Wing venation similar to Setodes scutatus n. sp. ( Figs. 9F, 9H ), except hind wing cell M1+2 short, such that cell R3 at least 1.5 times longer than cell M1+2 ( Fig. 8F arrows), tips of fore- and hind wings acute.

Male genitalia. Segment IX anterior margin concave and strongly reduced subdorsally at 4/5 height and posterior margin deeply indented at bases of lateral branches of segment X ( Figs. 8A, 8B ), in dorsal view with mesal 3/5 forming trapezoid plate ( Fig. 8B ), and with pair of setal warts near its anterior margin ( Figs. 8A, 8B ); broadly rectangular and nearly 2/3 as long as wide in ventral view ( Fig. 8C ). Preanal appendages apparently absent. Tergum X represented by pair of highly sclerotized lateral branches, each arising at 1/4 distance from dorsal margin of segment IX, fringed with long hair near midlength, and with forked apex ( Figs. 8A, 8B ); in dorsal view, branches slightly asymmetrical in respect to one another, stout at basal 1/2, each gradually narrowing to forked and subapically toothed apex ( Fig. 8B ). Inferior appendages short and set vertically, generally kidney shaped in lateral view; each with three branches positioned on dorsal half, two of them located on inner posterior margin of appendage, upper one finger-like with acute tip and lower one rod-like with truncate tip; longest, third branch arising between the other two in lateral view, slender, set on outer posterior margin near top; in addition, below these branches near middle of appendage, stout seta arising from long chaza on outer posterior margin, posterolateral margin below chalaza sinuous and with few setae ( Fig. 8A ). Phallobase plate-like, phallicata long, trough-like; arched about 90° in middle, with basal 1/2 about 2 times as broad as distal 1/3, with pair of small, triangular phallotremal sclerites embedded subapically in endophallic membranes; pair of parameres slender, almost as long as phallicata, each deeply divided into two branches proximate to each other in basal 3/4, divergent slightly near apices ( Figs. 8B, 8D ).

Holotype male. PR CHINA: Si-chuan Province : Chong-zhou City , Ji-guan-shan Town , An-zi River Natural Preserve Station, Shao-yao creek, 30.8018°N, 103.2192°E alt. 1540 m, 25 Aug. 2016, Coll. Xu J-h . Paratypes. Same data as holotype, 1 male.

Etymology. Greek, charax , noun in apposition, meaning pointed stake, referring to the branched and irregularly toothed apices of the lateral branches of male abdominal segment X.

Distribution. East Palearctic Biogeographic Region, Central China.

Figures

FIGURE 8. Setodes charax Yang & Morse, sp. n., male. 8A–8D, genitalia: 8A, left lateral; 8B, dorsal; 8C, ventral; 8D, phallus left lateral. 8F, Apex of right hind wing, dorsal.

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.