Dicranomyia (Erostrata) yazuensis, Kato & Tachi & Gelhaus, 2018

Kato, Daichi, Tachi, Takuji & Gelhaus, Jon, 2018, Revision of the subgenus Dicranomyia (Erostrata) Savchenko, 1976 (Diptera, Limoniidae) of Japan, Zootaxa 4441 (1), pp. 181-194 : 190-192

Dicranomyia (Erostrata) yazuensis sp. nov.

( Figs. 29–34 , 40 , 43 )

Specimens examined: Holotype, male, JAPAN, Tottori, Yazu-chô, Mt. Ôgino-sen , 17.IX.2014, D. Kato ( BLKU) . Paratype, female, JAPAN: [ Honshu ], same data as holotype .

Diagnosis. General coloration ( Fig. 40 ) dark brown. Head largely blackened on vertex; palpus two segmented. Thorax with postpronotum and ventral half of pleuron pale yellow. Abdomen with sternites paler. Male genitalia ( Fig. 29 ) with tergite 9 bearing a pair of rounded lobes at middle of posterior margin; gonostylus wide on basal 3/5, apical 2/3 strongly narrowed and gently curved. Ovipositor ( Figs. 32–34 ) with cercus weakly curved dorsally; sternite 8 densely covered with setae; hypogynial valve long, about twice as long as sternite 8; furca bent medially on lateral margins, extending to base of cercus.

Description. Male. Body length 4.0 mm. Wing length 4.8 mm.

Head. Blackish brown, rostrum, palpus, and anterior part of vertex dark brown; antenna with scape and pedicel brown, base of scape paler, pedicel about 1.5 times as wide as basal half of flagellomeres, flagellar segments dark brown, with distinct pubescence; palpus two segmented, distal one shorter than basal one.

Thorax. Antepronotum and prescutum blackish brown, remainders of mesonotum dark brown; postpronotum pale yellow; pleuron largely pale yellow, dark on dorsal half, dorsopleural membrane and dorsal margin of anepimeron slightly paler than darkened part. Wing brownish hyaline. Legs with coxae and trochanters pale yellow, femora pale brown, tibiae and tarsi brown to dark brown. Halter dark on knob, base of the stem paler.

Abdomen. Tergites dark brown, sternites paler; posterior part of sternite 7 concaved into long triangle notch, without internal sac on posterior end. Male genitalia ( Fig. 29 ) with tergite 9 slightly wider than long, weakly narrowed toward bilobed caudal margin, each lobe rounded, about 1/3 as wide as tergite 9, interspace between lobes much shorter than width of lobe; gonocoxite cylindrical, longer than width of tergite 9, ventromesal lobe long and finger-shaped, about 1/2 as long as gonocoxite and about three times as long as width; gonostylus shorter than gonocoxite, distal 2/3 strongly narrowed to tip, tip pointed and weakly curved medially, outer-dorsal surface with a small protuberance bearing a seta at basal 1/3; paramere ( Figs. 30–31 ) with mesal-apical lobe long and slender, weakly curved dorsally, lateral side of paramere not produced; aedeagus ( Fig. 30 ) cylindrical, slightly narrowed toward tip, tip bilobed, directed ventrally.

Female. Body length: 4.5 mm. Wing length: 4.5 mm.

Almost same as male except terminalia. Ovipositor ( Figs. 32–34 ) brown to dark brown; tergite 10 in lateral view narrow, about half height of tergite 8, weakly tapered near tip, with three pairs of long setae on posterior margin; cercus slightly longer than sternite 8, curved dorsally on distal half, extending beyond tip of hypogynial valve, ventral margin hairy on basal 4/5; sternite 8 densely setigerous and horizontally long square, about 1.3 times as wide as length, with a pair of distinct internal ridge; hypogynial valve long, about twice as long as sternite 8, tip acute, basal part of the valve higher than tergite 10 in lateral view; furca about 1.3 as long as width, narrowed to setigerous tip, extending to base of cercus, lateral margin bent medially.

Distribution. Japan (Honshu ( Fig. 43 )).

Etymology. This species is named after the type locality.

Remarks. This species has the gonostylus with a protuberance bearing a single seta while the other Japanese species have two setae. However, we regard this species as a member of Erostrata Savchenko because its other features are consistent with the general description of the subgenus. This species is similar to Limonia striopleura Edwards, 1919 ( Indonesia, Malaysia) and Limonia congesta Alexander, 1967 ( India) in terms of body colorations and structures, both of which were described from females without associated male and probably belong to Erostrata based on their non-genitalic characters. However, this species is differentiated from them by the head entirely dark brown (yellowish in L. striopleura and L. congesta ), short distal segment of palpus (longer than the basal one in L. congesta ), tarsi lacking bands (with white bands in L. congesta ), and cercus projecting beyond tip of the hypogynial valve (not beyond the tip in L. striopleura ).

Figures

FIGURES 29–34. Male genitalia and female ovipositor of Dicranomyia (Erostrata) yazuensis sp. nov. 29: Male genitalia (holotype) in dorsal view; 30: Internal structure of male genitalia in dorsal view; 31: Paramere of male genitalia in outer view; 32: Female ovipositor (paratype) in lateral view; 33: Sternite 8 and hypogynial valve in ventral view; 34: Furca in ventral view. Scale bars = 0.1 mm.

FIGURES 35–40. Adults of Dicranomyia (Erostrata) spp. 35: D. (E.) globithorax; 36: D. (E.) globulithorax; 37: D. (E.) submelas sp. nov.; 38: D. (E.) reniformis sp. nov.; 39: D. (E.) tabashii; 40: D. (E.) yazuensis sp. nov. Scale bars = 2 mm.

FIGURES 41–44. Distributions of Japanese species of Dicranomyia (Erostrata). 41: D. (E.) globithorax (red circle) and D. (E.) globulithorax (blue triangle); 42: D. (E.) submelas sp. nov.; 43: D. (E.) reniformis sp. nov. (red circle) and D. (E.) yazuensis sp. nov. (blue triangle); 44: D. (E.) tabashii.