Stactobiella aichi, Ito, 2020

Ito, Tomiko, 2020, The genus Stactobiella Martynov (Trichoptera, Hydroptilidae) in Japan, Zootaxa 4748 (3), pp. 561-571 : 565-566

Stactobiella aichi sp. nov.

( Figs 3 , 6 )

Diagnosis. The male of this species resembles that of Stactobiella alasignata Botosaneanu, 1993 , described from Primorye, Russian Far East, in having a strongly curved subgenital plate and broad, leaf-like inferior appendages, but is clearly distinguished from S. alasignata as follows: Segment IX has lateral processds in S. aichi , but segment IX is without any processes in S. alasignata .

Adult. Wings and antennae brown. In males (n=3), forewings each 2.1–2.2 mm long and hind wings each 1.9–2.0 mm long; antennae each 18-segmented, 1.2–1.4 mm long. Short ventral process on abdominal segment VII in male.

Male ( Fig. 3 ). Segment IX shorter than segment VIII, with pair of long anterior apodemes; tergite IX with lateral processes, with rounded ventral sclerite mesally. Segment X membranous, subquadrate. Subgenital plate heavily sclerotized, thick, directed ventrad at first and strongly curved anterad medially. Inferior appendages broadly leaflike, with many marginal setae in ventral view, leaf-like with dorso-caudal lobe in lateral view. Aedeagus almost straight, slightly thickened at apical 1/4 and tapered distally, with deep concavity apically.

Female. Unknown.

Holotype. Male, Japan, Honshu, Aichi, Shinshiro-shi, Toyooka , Ichinose , Ôtsutani-gawa , near river mouth (34.990556 N, 137.624722 E, 129 m above sea level.), 18.vii.2013, T. Ito, light pan trap. (CBM-ZI 0178571).

Paratypes. 2 males, same data as holotype (CBM-ZI 0178572–0178573) .

Other specimens. Honshu, Aichi : 1 male, type locality, 1.vi.2014, H. Nishimoto, light trap; 1 male, type locality, 17.viii.2004, H. Nishimoto. Shizuoka : 1 male, Shizuoka-shi, Yunoshima, Warashina-gawa, 280 m, 19.viii.1997, T. Hattori. Hyogo : 1 male, Himeji-shi, Yumemae-cho, 23.viii.2016, M. Matsuoka & I. Kawano.

Distribution ( Fig. 6 ). Japan (Honshu).

Habitat. Adults of this species were collected beside rapid streams, flowing over bed rock.

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

Japanese name. Aichi-sawa-himetobikera.

Figures

FIGURE 3. Stactobiella aichi sp. nov., male. 3A, genitalia, left lateral; 3B, same, dorsal; 3C, same, ventral; 3D, apical part of aedeagus, dorsal. Abbreviations: VII–X=abdominal segments VII–X; ae=aedeagus; ia=inferior appendage (paired); lp=lateral process (paired); sp=subgenital plate; vs=ventral sclerite. Scale bar, 0.1 mm.

FIGURE 6. Distributions of five species of the genus Stactobiella in Japan and neighboring countries. Symbols in Russia, Mongolia and China are cited from references.