Cheumatopsyche aira Ito and Nozaki, 2018

Ito, Tomiko & Nozaki, Takao, 2018, The family Hydropsychidae Curtis (Trichoptera) in the Ryukyu Archipelago, southwestern Japan, Zootaxa 4504 (4), pp. 545-565 : 556-558

Cheumatopsyche aira Ito and Nozaki sp. nov.

( Figs 6 A– 6I)

Diagnosis. The male of this species is similar to that of Cheumatopsyche clavalis Martynov 1930 , originally described from Taiwan, in having an almost straight posterior margin on each side of segment IX and low mesocaudal lobes of segment X (m.c.l.) ( Kobayashi 1987; Oláh et al. 2008). However, C. aira is clearly discriminated from C. clavalis as follows: Each lateral lobe of segment X (l.l.) is short, round, widely separated with each other in dorsal aspect in C. aira , but moderately long with apicomesal acute corner, closely contacted each other in dorsal aspect in C. clavalis ; distal segment of each inferior appendage is nearly parallel sided and subquadrate apically in C. aira , but tapered and acute apically in C. clavalis .

Adult ( Figs 6 A– 6I). Wings brown, many light brown dots and patterns present mainly along margins in forewings, but often indistinct in alcohol specimens; light brown dots absent in hind wings. In males, forewings 5.5–6.3 mm long and hind wings 4.2–4.8 mm long (n = 5); apical forks I–V present, discoidal cell small, medial cell open in forewings; apical forks II, III and V present, discoidal cell short in hind wings. In females, forewings 5.8–6.2 mm long and hind wings 4.3–4.7 mm long (n = 5); apical forks I–V present, discoidal cell small, medial cell longer than discoidal cell in forewing; apical forks II, III and V present, discoidal cell short in hind wing.

Male genitalia ( Figs 6 B–6F). Segment IX short with gently protruding anterior margins and nearly straight caudal margins in lateral aspect. Segment X with very short mesocaudal lobe (m.c.l.) in lateral and dorsal aspects; lateral lobes (l.l.) short, with length almost as long as width and oval and widely separated each other in dorsal aspect, bar-like in lateral aspect. Inferior appendages slender, directed postero-dorsad in lateral aspect and gently curved posteromesad in ventral aspect; basal segment long, 3.3 times of distal segment; distal segment more slender than basal segment, almost parallel sided in ventral aspect, slightly curved in lateral aspect, each with apex subquadrate. Phallic apparatus with short endothecal process (e.p.), phallotremal sclerite (p.s.) C- and reverse Cshaped in ventral aspect; numerous very small spines on apical part of phallotheca ventrally.

Female genitalia ( Figs 6 H– 6I). Tergite VIII with almost straight anterior margins and convex caudal margins in lateral aspect. Sternite VIII subquadrate, larger than tergite VIII, with oblique straight dorsal margin and large subquadrate lateral lobes in lateral aspect, triangular lateral lobes in ventral aspect, each lobe wide at anterior margin, mesal margin gently curved laterad. Segment IX obliquely S-shaped in lateral aspects. Receptacle of inferior appendage (rec.) distinct, nearly question mark shaped in lateral aspect. Segment X oblique rectangular.

Holotype: Male, Iriomote-jima, Taketomi-cho, Aira-gawa (24.3332N, 123.9134E, 5 m a.s.l.), 28–30.x.2012, TI, P ( CBM-ZI 166013 ).

Paratypes. 5 males, 5 females, same data as holotype ( CBM-ZI 166014–166023 ) .

Other specimens examined. Iriomote-jima: 17 males, 271 females, same data as holotype ; 9 males, 7 females, type locality, 25.iii.1999, TI & AO, L; 2 males, 2 females, type locality, 28.xi–2.xii.2013, TI & RS, M; 3 males, 18 females, type locality, 21–22.iii.2016, TI , P; 12 males, 13 females, type locality, 20–24.x.2016, TI , P; 2 males, 15 females, Aira-gawa, 25–45 m, a.s.l., 1.xii.2013, TI , L, P & S; 11 males, 11 females, same locality, 21.x.2015, TI & RS, L; 12 males, 31 females, same locality, 21.iii.2016, TI , L; 1 male, 16 females, Aira-gawa, 15.iii.2002, I. Oshima et al., L; 10 males, 8 females, same locality, 27.v.2009, K. Tojo, L ; 2 males, 3 females, Nishi-funatsuki-gawa, Nishi-funatsuki-bashi, 23.iii.1999, TI & AO, L; 4 females, same locality, 23.iii.2016, TI , L; 1 female, Maera-gawa, 9 m a.s.l., 28.x.2012, TI , L; 4 males, 2 females, Yuchin-gawa, 10 m a.s.l., 23.x.2015, TI , L; 5 males, 4 females, same locality, 22.x.2016, TI , L; 19 males, 25 females, Omijya-gawa, Omijya-bashi, 24.iii.1999, TI & AO, L; 3 females, same locality, 26.v.2009, K. Tojo, L ; 8 females, same locality, 29.x.2012, TI , P; 1 female, same locality, 30.xi.2013, TI , P; 2 females, same locality, 21.x.2015, TI ; 5 females, same locality, 23.iii.2016, TI , P.

Etymology. The name “ aira ” is a noun in apposition, coined from the type locality.

Distribution. Japan: Ryukyu (Iriomote-jima). Endemic to southern Ryukyu.

Remarks. This is the most common hydropsychid caddisflies in Iriomote-jima and sometimes is collected together with C. clavalis .

Japanese name. Aira-kogata-shima-tobikera.

Figures

FIGURE 6. Cheumatopsyche aira Ito & Nozaki sp. nov. Male (6A–6F): 6A, right wings, dorsal, light color marks of forewing, venations of forewing and hind wing; 6B, genitalia, left lateral; 6C, same, dorsal; 6D, left inferior appendage, ventral; 6E, phallic apparatus, left lateral; 6F, apical part of phallus, ventral. Female (6G–6I): 6G, right wings, dorsal; 6H, genitalia, left lateral; 6I, same, ventral. Abbreviations: I–V = apical forks I–V; VIII–X = abdominal segments VIII–X; e.p. = endothecal process (paired); l.l. = lateral lobe (paired); m.c.l. = mesocaudal lobe; p.s. = phallotremal sclerite.