Ecnomus hokkaidensis, Kuhara, Naotoshi, 2016

Kuhara, Naotoshi, 2016, Revision of Japanese species of the genus Ecnomus McLachlan (Trichoptera: Ecnomidae), with descriptions of two new species, Zootaxa 4114 (5), pp. 561-571 : 561-564

publication ID	https://doi.org/10.11646/zootaxa.4114.5.2
publication LSID	lsid:zoobank.org:pub:8F1A8843-F034-4C7B-A1F9-F39548E3F2C0
DOI	https://doi.org/10.5281/zenodo.6069232
persistent identifier	https://treatment.plazi.org/id/03F39E16-FFA7-F25D-0D97-F8B6FB08FF33
treatment provided by	Plazi (2016-05-26 06:09:48, last updated 2024-11-25 20:28:17)
scientific name	Ecnomus hokkaidensis
status	sp. nov.

Treatment

Ecnomus hokkaidensis sp. nov.

( Figs. 1 View FIGURE 1 A–J, 6)

Ecnomus sp.: Kuhara et al. 2007, appendix 69.

Diagnosis. The male of this species is very similar to that of E. tenellus , but can be distinguished from it by the shape and structure of the inferior appendages. In E. hokkaidensis , each inferior appendage bears a spatulate projection basodorsally, whereas E. tenellus has an ear-like dorsal projection at midlength. In ventral aspect, the inferior appendages are relatively longer and more slender and are angled abruptly inward at midlength in E. hokkaidensis , but they are stouter and smoothly curved in E. tenellus . The female of this species is characterized by sternum VII with 2 ventromesal plates.

Description. Adult ( Fig. 1 View FIGURE 1 ). Length of each forewing of male 4.5–5.7 mm (mean = 5.0 mm, n = 17), female 4.7–5.5 mm (mean = 5.0 mm, n = 14). Head frons with single frontal wart, pair of ellipsoidal dorsal hypomedial warts, and indistinct pair of small ventral hypomedial warts; vertex with pairs of oval antennal, preocellar, ocellar, and occipital warts ( Figs. 1 View FIGURE 1 A, 1B). Pronotum with 2 pairs of warts; lateral warts indistinct laterally; medial warts round; mesonotum with pair of round scutal warts and pair of semicircular scutellar warts ( Fig. 1 View FIGURE 1 A). Legs with tibial spur formula 3, 4, 4. Forewings each with fork of R1 and forks I, II, III, IV and V, discoidal cell, median cell and thyridial cell; crossvein m-cu near bifurcation of medial vein; hind wings with forks II and V ( Fig. 1 View FIGURE 1 C).

Male genitalia ( Figs. 1 View FIGURE 1 D–H). Tergum IX long, reaching posterior margin of sternum IX ( Fig. 1 View FIGURE 1 D); anterodorsal margin deeply and widely excised ( Fig. 1 View FIGURE 1 E); sternum IX drop-shaped in lateral aspect ( Fig. 1 View FIGURE 1 D), with longitudinal median line in ventral aspect ( Fig.1 View FIGURE 1 F); anteroventral margin deeply notched; posteroventral margin shallowly and broadly excised ( Fig. 1 View FIGURE 1 F). Segment X with pair of finger-shaped posteroventral projections, each weakly bent inward at midlength and with 2 setae apically; anterolateral arms curved outward anteriorly ( Fig. 1 View FIGURE 1 E). Superior appendages elongate-triangular, tapering to blunt apices in lateral aspect ( Fig. 1 View FIGURE 1 D); mesal surfaces concave, each with short triangular projection near base bearing 3 apical setae ( Fig. 1 View FIGURE 1 E); stout setae arising from apical and dorsal margins in distal 2/5 ( Figs. 1 View FIGURE 1 D, 1E). Inferior appendages subequal in length with superior appendages; each elongate, slightly upcurved, thick basally, constricted medially in lateral aspect ( Fig. 1 View FIGURE 1 D); with outer margin abruptly angled 45° inward at midlength, tapered to blunt apex in ventral aspect ( Fig. 1 View FIGURE 1 F); with mesally-directed spatulate projection basodorsally ( Fig. 1 View FIGURE 1 G). Basal plate of inferior appendages sclerotized, with pair of small triangular projections laterally 1/3rd distance from anterior end ( Figs. 1 View FIGURE 1 F, 1G); with pair of small, longitudinal, posterodorsal projections directed anteromesad and bearing setae along margins ( Fig. 1 View FIGURE 1 H). Phallus with strongly sclerotized phallobase, tubular, curved downward ( Fig. 1 View FIGURE 1 H); distal 1/3 flattened dorsoventrally and spoon-shaped ( Fig. 1 View FIGURE 1 G); parameres and basodorsal lobes absent.

Female genitalia ( Figs. 1 View FIGURE 1 I, 1J). Sternum VII with 2 distinctly pigmented ventromesal plates; anterior plate oval; posterior plate wide, concave anteriorly with posterolateral extensions in ventral aspect ( Fig. 1 View FIGURE 1 J). Ventral plates of sternum VIII suboval, each with 3 long setae along apical margin ( Fig. 1 View FIGURE 1 J). Segment XI setose, unpigmented with narrow, oblique, sclerotized bands anterolaterally ( Fig. 1 View FIGURE 1 I).

Holotype. male (pinned), Japan, Hokkaidô, Ishikari, Chitose-shi, Shikotsu-ko, Poropinai, 42.80ºN, 141.34ºE, 14.viii.2006, NK ( SEHU).

Paratypes. 1 male (pinned), type locality, 12.viii.2005, NK ( SEHU); 14 males (in alcohol), type locality, 10.viii.2005, NK ( CBM); 4 males, type locality, 5.viii.2005, NK ( SEHU).

Other specimens. [Hokkaidô] Kushiro: 2 males, Kushiro-chô, Hokuchiku-ura, 15.viii.2007, T. Kosugi; 6 males, 11 females, Kushiro-chô, Kushiro-gawa, 15.viii.2007, TI & T. Kosugi; 2 males, 2 females, Kushiro-chô, Takkobu-numa, 8.viii.2006, TI; 2 males, 1 female, Kushiro-shi, Iwabokki, 3.vii.1987, M. Itou; 1 female, Shibechachô, Shirarutoro-ko, 7.vii.2006, TI. Sôya: 2 males, Sarufutsu-mura, Narita-gawa, Kaede-bashi, 31.vii.2007, NK & TI; 1 female, Sarufutsu-mura, Asajino, outlet of Kamuito-numa, 31.vii.2007, NK; 3 males, 4 females, Sarufutsumura, pond nr. Sarufutsu-gawa, 31.vii.2007, NK; 10 males, 2 females, Sarufutsu-mura, Sarufutsu-2-gôsen-gawa, Shôbu-bashi, 31.vii.2007, NK & TI. Rumoi: 6 males, 15 females, Rumoi-shi, Ôwada, el. 9-10 m, 2.viii.2015, NK. Ishikari: 2 males, 4 females, type locality, 5.viii.2005, NK; 1 male, 6 females, ibid, 12.viii.2005, NK; 1 female, ibid, 17.viii.2005, NK; 1 male, 2 females, ibid, 14.viii.2006, NK; 1 male, Chitose-shi, Shikotsu-ko, Okotan, 29.vii.1990, NK; 1 female, Chitose-shi, Shikotsu-ko, Shikotsuko-onsen, 9.viii.2006, NK; 6 males, 2 females, Chitose-shi, Shikotsu-ko, Shishamonai, 5.viii.2005, NK; 8 males, 12 females, ibid, 10.viii.2006, NK; 1 male, Eniwa-shi, Izari-gawa, el. 130 m, 2.viii.2015, TI; 1 male, Eniwa-shi, Izari-gawa, el. 170 m, 17.vii.2015, TI.

Etymology. Named for its distribution in Hokkaidô.

Distribution. Japan: Hokkaidô.

Habitat. Adults of this species have been collected beside slow flowing streams or rivers and shorelines of a pond in the Kushiro Marsh, Kushiro, and Lake Shikotsu-ko, Ishikari.

Remarks. The downward curved phallus with spoon-shaped apex indicates this species belongs to the E. tenellus Group of Li & Morse (1997). This is the fourth species in the Group distributed in the East Palaearctic region, as a result of E. tsudai and E. kososiensis becoming invalid names as discussed below.

References

Kuhara, N., Nagayasu, Y. & Ito, T. (2007) Shikotsu-ko to Shikotsu-ko ryunyu kasen no tobikera mokuroku (A list of caddisflies collected in Shikotsu-ko and streams flowing into the lake). In: The Editing Committee of Nature and Lives in Lake Shikotsu-ko (Ed.), Nature and Lives in Lake Shikotsu-ko. Study Group of the Chip and the Water of Lake Shikotsu-ko, Sapporo, pp. 65 - 74 (appendix). [in Japanese]

Li, Y. J. & Morse, J. C. (1997) Species of the genus Ecnomus (Trichoptera: Ecnomidae) from the People's Republic of China. Transactions of the American Entomological Society, 123, 85 - 134.

Figures

FIGURE 1. Ecnomus hokkaidensis sp. nov. (type locality; 1 D – 1 F, holotype). 1 A, head, prothorax and mesothorax, dorsal; 1 B, head, frontal; 1 C, right wings, venation, dorsal; 1 D – 1 F, male genitalia: 1 D, left lateral; 1 E, dorsal; 1 F, ventral; 1 G – 1 H, male phallus and inferior appendages: 1 G, dorsal; 1 H, left lateral; 1 I – 1 J, female genitalia: 1 I, left lateral; 1 J, ventral. Abbreviations: DC = discoidal cell; MC = median cell; TC = thyridial cell; m-cu = crossvein m-cu; f R 1 = fork of R 1; F 1 – F 5 = fork 1 – fork 5.