Diplectrona uken 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 : 549-551

Diplectrona uken Ito and Nozaki sp. nov.

( Fig. 3 A– 3I)

Diagnosis. The male of this species is similar to that of Diplectrona erinya Malicky 2002 from Vietnam in that segment V is longer than its lateral filaments and lacking internal glands, and also in the mid-sized internal glands of segment VIII, and the shape of genitalia (Malicky 2 002). However, the male genitalia of D. uken are clearly discriminated from those of D. erinya as follows: Segment X is divided into one pair of large lobes, each is subtriangular with its inner margin having a stout protuberance subapically in dorsal aspect, and the phallic apparatus with complicated inner sclerites in D. uken ; but the lobes of segment X are almost rectangular in dorsal aspect and the phallic apparatus is without such sclerites in D. erinya ( Malicky 2002, Malicky personal communication 22 November 2017).

Adult ( Figs 3 A– 3I). Wings brown, several light brown dots and patterns present in forewings, but often indistinct in alcohol specimens. Forewings 4.3–5.6 mm long (n = 5); apical forks I–V present, discoidal cell short, medial cell long in forewings; apical forks I, II, III and V present, discoidal cell long in hind wings. Lateral filaments of segment V slightly shorter than the segment, internal glands of segment V absent, internal glands of segment VIII middle-sized.

Male genitalia ( Figs 3 C– 3I). Segment IX short, anterior margin slightly protruded at ventral 1/4, posterior margin undulating through ventral 2/ 5 in lateral aspect. Segment X in lateral aspect with upper margin round and dorsal subapex deeply concave, ventrolateral margin sinuous; in dorsal aspect divided into 2 large lobes, each subtriangular with subapical protuberance on mesal edge; shape of protuberances and their apices variable individually, from almost reduced to fairly developed ( Figs 3D, 3E, and 3F ), even opposite ones of left and right lobes within single specimen. Inferior appendages with long basal and short distal segments; basal segment nearly straight and gradually thickened from base to apex in lateral aspect, and slightly swollen at apical 1/ 3 in ventral aspect; distal segment in lateral aspect about 1/6 as long as basal one, with upper and ventral margins almost parallel, and apex round, in ventral aspects width about half width of basal segment, slender and slightly curved mesad. Phallic apparatus evenly thick, with pair of small endothecal processes (e.p.) apicodorsally; internal sclerites large and complicated.

Female. Unknown.

Holotype: Male, Amami-o-shima, Uken-son, Yuwan, Kawauchi-gawa, upper reach, 28.2553N, 129.3511E, about 100 m a.s.l., 2.vii.2017, N. Katsuma, L ( CBM-ZI 166024 ).

Paratypes. 2 males, same data as holotype ( CBM-ZI 166025–166026 ) .

Other specimens examined. Amami-o-shima: 2 males, same data as holotype. Iriomote-jima : 1 male, Urauchi-gawa , small stream near Boat Station, 18.x.2005, TI , S.

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

Distribution. Japan: Ryukyu (Amami-o-shima, Iriomote-jima). Endemic to the central and southern Ryukyu.

Japanese name. Uken-miyama-shima-tobikera.

Figures

FIGURE 3. Diplectrona uken Ito & Nozaki sp. nov., male. 3A, right wings, dorsal, venation and light color marks; 3B, abdominal segments V–X, left lateral; 3C, genitalia, left lateral; 3D, same, dorsal (holotype); 3E, segment X, dorsal, variation (type locality); 3F, same (Iriomote-jima); 3G, left inferior appendage, ventral; 3H, phallic apparatus, left lateral; 3I, apical 2/3 of phallic apparatus, ventral. Abbreviations: I–V = apical forks I–V in 3A; V–X = abdominal segments V–X in 3B– 3D; e.p. = endothecal process (paired).