Homoplectra occidens, Nozaki, 2019

Nozaki, Takao, 2019, Descriptions of five new species of Homoplectra Ross (Trichoptera, Hydropsychidae) from Japan with reassignment of Homoplectra tohokuensis (Kobayashi), Zootaxa 4608 (2), pp. 329-344 : 338-339

Homoplectra occidens sp. nov.

( Figs. 5 , 9 )

Homoplectra sp.: Kawase et al. 2017, 32.

Homoplectra sp. B: Nojima 2017 119.

Diagnosis. The male of this species is somewhat similar to that of H. tohokuensis in the shape of the phallic apparatus, but it is easily distinguishable by the position of the posterior processes of segment X: The process arising from near the base in H. occidens sp. nov., but from nearer the dorsum in H. tohokuensis . The female of H. occidens sp. nov. is also similar to that of H. tohokuensis in the shape of segments VIII to X, but it is distinguishable from the latter by the size of the vaginal apparatus: The vaginal apparatus of this species is longer than that of H. tohokuensis , largely filling segment VII.

Adult. Body and forewings mostly dark brown in alcohol. Forewings each 5.7–7.0 mm long in male (n = 8), 5.5–8.0 mm long in female (n = 7). Venation similar to that of H. crassa sp. nov. Anterolateral processes of segment V with blunt apices, more than half as long as male sternum, less than half as long as female sternum.

Male genitalia. Sternum IX smoothly triangular in lateral aspect, with round anteolateral lobe on each side; posteroventral lobe large, triangular with blunt apex in ventral aspect. Tergum IX semicircular in dorsal aspect, broadly fused with segment X laterally. Segment X protruding posterodorsally; bilobed in dorsal aspect, each lobe with small acute posterior process near base. Inferior appendages long, without distal segment, each with ventromesal apex slightly bulging subapically and with short spine-like setae. Phallic apparatus strongly arcuate in lateral aspect, phallotheca with pair of dorsal processes slender, each with acute apex curved slightly ventrad; with pair of lateral processes, shorter than dorsal processes, each with acute apex, curved slightly ventrad apically. Aedeagus slender, with fingertip-like apex long, approximately 1/3 as long as basal stem, curved slightly downward; pair of broad lateral processes with basal 2/3 fused with aedeagus, each with apex concave subapicomesally, truncate in lateral aspect; plate-like process arising subapicoventrally on aedeagus, unpigmented.

Geographic variations in male genitalia. In males collected from Shiga Prefecture, the posteroventral lobe of sternum IX is trapezoidal in ventral aspect ( Fig. 5E 1 ), the lateral processes of the phallotheca are mostly straight ( Fig. 5F ), each lateral process of the aedeagus has an oblique apex in lateral aspect with a dorsal finger-like projection (marked with an arrow in Fig. 5F ), the aedeagus is without a plate-like ventral process but a small round process occurs ventrally (marked with an arrow in Fig. 5G ). In males collected from Okayama Prefecture, the posteroventral lobe of sternum IX is triangular with an acute apex ( Fig. 5E 2 ).

Female genitalia. Lateral lobes of sternum VIII triangular in ventral aspect, subapicomesal margins slightly jagged, basal 1/3 fused with segment VIII. Segment IX oblique, mucronate posteriorly in dorsal aspect, anteroventral projections blade-shaped in lateral aspect. Vulval scale large, posterior margin membranous. Vaginal apparatus round rectangular in ventral aspect, but with suddenly narrower anterior 1/3 protruding into segment VII.

Immature stages. Unknown.

Holotype. Male (in alcohol). Unawa, Yabu-shi , Hyogo, 35.3447°N, 134.5369°E, alt. 908 m, 11.vii.2004, K. Inazu ( CBM-ZI 0167083 .

Paratype. 1 male, 2 females, same data as holotype except collection date 6.vii.2003 ( CBM-ZI 0167084– 0167086 ) ; 1 male, Unawa, Yabu-shi , Hyogo, 35.3394°N, 134.5456°E, alt. 873 m, 2.vi.2009, K. Inazu ( CBM-ZI 0167087 ) ; 1 female, same locality, 1.vii.2007, K. Inazu .

Other specimens examined. Shiga: 2 males, Shiratani-rindo, Makino-cho-shiratani, Takashima-shi, 17.v.2014, S. Takeda (NaK) . Hyogo: 1 male, 2 females, same data as holotype except collection date 1.vii.2007 ( KI) . Okayama: 2 males, 2 females, Aba, Tsuyama-shi , 13.v.2016, K. Nojima ( KN) .

Etymology. The specific epithet (Latin, masculine noun in apposition, “west”) refers to the fact that this species was found in western Honshu, whereas a related species H. tohokuensis was collected from northeastern Honshu.

Distribution. Honshu (central to western).

Habitat. Adults of this species were collected by net sweeping near small waterfalls or seepages on a vertical rock surface at the type locality (Inazu personal communication 5.v.2018). Japanese name. Nishi-nisemiyama-shima-tobikera

Figures

FIGURE 1. Adults of Homoplectra crassa sp nov. 1A, male habitus, left lateral; 1B, male head and pro- and mesonota, dorsal; 1C, male right wings, dorsal; 1D, male sternum V, left lateral. 1E–1I, male genitalia, type locality (Tokyo, Hino-shi): 1E, left lateral, apicomesal part enlarged; 1F, dorsal; 1G, ventral; 1H, phallic apparatus, left lateral; 1I, same, dorsal, mesal margin of left dorsal process of phallotheca enlarged. 1J–1N, male genitalia, variations: 1J1, ventral lobe of segment IX, ventral, Kanagawa (Yokosuka-shi); 1J2, same, Nagano (Chino-shi); 1K1, segment X, left lateral, Kanagawa (Yokosuka-shi); 1K2, same, Shizuoka (Fujieda-shi); 1L, phallic apparatus, left lateral, Shizuoka (Fujieda-shi); 1M1, phallotheca, dorsal, Shizuoka (Fujieda-shi); 1M2, dorsal process of phallotheca, dorsal, Kanagawa (Yokosuka-shi); 1N1, aedeagus, dorsal, Shizuoka (Fujieda-shi); 1N2, same, Kanagawa (Yokosuka-shi); 1N3, same, Nagano (Chino-shi). 1O–1Q, female genitalia, type locality except as indicated: 1O, left lateral; 1P, dorsal; 1Q, ventral. 1R, female vaginal sclerite, ventral, Yamanashi (Hayakawa-machi). Abbreviations: ae. = aedeagus, d.p.p. = dorsal process of phallotheca (paired), end. = endotheca, i. a. = inferior appendage (paired), IX = abdominal segment IX, l.l. = lateral lobe of sternum VIII (paired), l.p.a = lateral process of aedeagus (paired), l.p.p, = lateral process of phallotheca (paired), p.l. = posteroventral lobe of sternum IX, ph. = phallotheca, p.p. = posterior process of segment X (paired), sIX = sternum IX, tIX = tergum IX, v.a. = vaginal apparatus; v.c. = vaginal chamber, v.s. = vulval scale, v.p.a. = ventral process of aedeagus, X = abdominal segment X.

FIGURE 9. Distributions of Homoplectra species in Japanese main islands.

FIGURES 4–5. Adults of Homoplectra spp. 4A–4H, Homoplectra tohokuensis (Kobayashi 1973). 4A–4E, male genitalia: 4A, left lateral; 4B, dorsal; 4C, ventral; 4D, apical half of phallic apparatus, left lateral; 4E, same, dorsal. 4F–4H, female genitalia: 4F, left lateral, 4G, dorsal; 4H, ventral. 5A–5J, Homoplectra occidens sp. nov. 5A–5D, male genitalia, type locality: 5A, left lateral; 5B, dorsal; 5C, ventral; 5D, phallic apparatus, dorsal. 5E–5G, male genitalia, variations: 5E1, posteroventral lobe of abdominal segment IX, ventral, Shiga (Takashima-shi); 5E2, same, Okayama (Tsuyama-shi); 5F, apical half of phallic apparatus, left lateral, Shiga (Takashima-shi); 5G, apical part of aedeagus, ventral, Shiga (Takashima-shi). 5H–5J, female genitalia, type locality: 5H, left lateral; 5I, dorsal; 5J, ventral. Arrows see text.

FIGURES 2–3. 2A–2L, adults of Homoplectra ise sp. nov. 2A–2E, male genitalia, type locality (Mie, Minamiise-cho): 2A, left lateral; 2B, dorsal; 2C, ventral; 2D, phallic apparatus, left lateral; 2E, same, dorsal. 2F–2I, male genitalia, variations: 2F1, segment X, left lateral, Ehime (Uchiko-cho); 2G1, apical half of phallotheca, dorsal, Mie (Iga-shi); 2G2, same, Mie (Matsuzaka-shi); 2G3, same, Ehime (Uchiko-cho); 2H1, aedeagus, dorsal, Mie (Iga-shi); 2H2, same, Mie (Matsuzaka-shi); 2H3, same, Ehime (Uchiko-cho); 2I, ventral process of aedeagus, ventral, Ehime (Uchiko-cho). 2J–2L, female genitalia, type locality: 2J, left lateral; 2K, dorsal; 2L, ventral. 3A–3F, male genitalia of Homoplectra hattorii sp. nov. type locality (Hokkaido, Ashibetsu-shi): 3A, left lateral; 3B, dorsal; 3C, ventral; 3D, phallic apparatus, left lateral; 3E, same, dorsal; 3F, aedeagus, dorsal. Abbreviations: ae. = aedeagus, d.p.a. = dorsal process of aedeagus (paired), d.p.p. = dorsal process of phallotheca (paired), end. = endotheca, i. a. = inferior appendage (paired), l.p.a = lateral process of aedeagus (paired), l.p.p, = lateral process of phallotheca (paired), ph. = phallotheca, p.p. = posterior process of segment X (paired).