Ecnomus hokkaidensis Kuhara, 2016, sp. nov.
Creators: name: Kuhara, Naotoshi
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Trichoptera
Ecnomidae
Ecnomus
Ecnomus hokkaidensis

description: Ecnomus hokkaidensis sp. nov.
(Figs. 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). 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 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 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 C).
Male genitalia (Figs. 1 D–H). Tergum IX long, reaching posterior margin of sternum IX (Fig. 1 D); anterodorsal margin deeply and widely excised (Fig. 1 E); sternum IX drop-shaped in lateral aspect (Fig. 1 D), with longitudinal median line in ventral aspect (Fig.1 F); anteroventral margin deeply notched; posteroventral margin shallowly and broadly excised (Fig. 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 E). Superior appendages elongate-triangular, tapering to blunt apices in lateral aspect (Fig. 1 D); mesal surfaces concave, each with short triangular projection near base bearing 3 apical setae (Fig. 1 E); stout setae arising from apical and dorsal margins in distal 2/5 (Figs. 1 D, 1E). Inferior appendages subequal in length with superior appendages; each elongate, slightly upcurved, thick basally, constricted medially in lateral aspect (Fig. 1 D); with outer margin abruptly angled 45° inward at midlength, tapered to blunt apex in ventral aspect (Fig. 1 F); with mesally-directed spatulate projection basodorsally (Fig. 1 G). Basal plate of inferior appendages sclerotized, with pair of small triangular projections laterally 1/3rd distance from anterior end (Figs. 1 F, 1G); with pair of small, longitudinal, posterodorsal projections directed anteromesad and bearing setae along margins (Fig. 1 H). Phallus with strongly sclerotized phallobase, tubular, curved downward (Fig. 1 H); distal 1/3 flattened dorsoventrally and spoon-shaped (Fig. 1 G); parameres and basodorsal lobes absent.
Female genitalia (Figs. 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 J). Ventral plates of sternum VIII suboval, each with 3 long setae along apical margin (Fig. 1 J). Segment XI setose, unpigmented with narrow, oblique, sclerotized bands anterolaterally (Fig. 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.
description: Published as part of Kuhara, Naotoshi, 2016, Revision of Japanese species of the genus Ecnomus McLachlan (Trichoptera: Ecnomidae), with descriptions of two new species, pp. 561-571 in Zootaxa 4114 (5) on pages 561-564, DOI: 10.11646/zootaxa.4114.5.2, http://zenodo.org/record/265300