Tipulodina bifurcata Xue & Men

Xue, Guo-Xi, Men, Qiu-Lei, Zhang, Jia, Zhao, Qing, Sheng, Nan, Wang, Hai-Xiao & Long, Ji-Feng, 2019, A new species of Tipulodina (Diptera, Tipulidae) from China, with description of the female internal reproductive system, ZooKeys 864, pp. 67-77 : 67

Tipulodina bifurcata Xue & Men sp. nov. Figs 1-8, 9-16, 17-20, 22-24

Material examined.

Holotype: male. CHINA: Guangxi, Longzhou County, Nonggang National Nature Reserve, 9 April 2018, leg. Guoxi Xue. Paratype: 1 female, same data to holotype.

Diagnosis.

The only male specimen of Tipulodina with the following combination of characters: antenna with scape white on basal two thirds, black on apical third, remaining segments black; prescutum with three brown stripes, median one divided by a narrow black vitta; wing transparent, stigma black, wing tip suffused with black on outer ends of cells r1, r4 and r5; fore and mid tibia with one white ring near apex, hind femora with two white rings; tergite nine shallowly emarginated on hind margin, densely covered with black setae; appendage of gonocoxite with a long horn-shaped rod, curved, black, sharply acute at apex, fringed with long yellow setae, with black bifurcate process inserted basally.

Description.

Male. Length: body 13.1 mm (not including antenna, n = 1); wing 12.3 mm (n = 1); antenna 3.3 mm (n = 1).

Head. Rostrum white with white nasus, densely covered with black setae. Eye black. Occiput light brown (Fig. 1). Vertex light brown, medially with narrow pale line (Fig. 1). Antenna: bent backward extended beyond base of first abdominal segment; scape white on proximal two thirds, gradually changed to black on distal third, cylindrical, slightly expanded at apex; pedicel black, very short; flagellum entirely black, first flagellomere longest, subequal in length to scape, remaining segments progressively shortened, bases of each flagellomere with five black verticils, of which longest one significantly shorter than its corresponding flagellomere, surface of each flagellomere densely covered with short black setae. Palpus white, three basal segments distinctly thicker than apical segment.

Thorax. Pronotum white laterally, black on middle third (Fig. 2). Prescutum white with three brown stripes; median one with lateral margins parallel, anterior margin suffused with black, black median vitta dividing by median stripe into two parts; lateral stripes half the length of median one, their apices also black (Fig. 2). Scutum white anteriorly and medially, with two light brown markings connected to each other, upper one distinctly smaller than lower one. Scutellum entirely white (Fig. 2). Postnotum wholly dark brown. Pleuron white, with two brown stripes, anterior stripe extending throughout the anterior spiracle, anepisternum and katepisternum, posterior stripe throughout posterior spiracle, laterotergite and hind coxa (Fig. 3). Legs very slender, coxae and trochanters white, the latter narrowly margined with black at apex (Figs 6-8); fore and mid legs with femora brown at base, gradually changed into black, with white ring near apex, tibiae black with white ring at apex, basitarsi black on proximal four fifths, white on distal fifth, remaining segments white (Figs 6, 7); hind leg with femur brown at base, brown becoming darker on distal portion, tibia black with two white rings, basal one slightly shorter than apical one, the latter reaching end of tibia, basitarsus black on basal four fifths, white on apical fifth, remaining tarsomeres white (Fig. 8). Halter with stem brown, knob darker. Wing glassy and transparent, stigma black, wing tip tinged with black on outer ends of cells r1, r4 and r5, light spot situated in middle of black region of cell r4; discal cell transparent, broadened. Venation: Rs very short, R3 reduced, petiole of cell m1 slightly shorter than discal cell, the latter slightly longer than cell m1 (Fig. 4).

Abdomen. Tergite 1 yellowish brown, dark on both anterior corners, tergite 2 yellowish brown, encircled in yellow medially and ringed with yellow at base, tergites 3 and 4 yellowish brown, narrowly suffused with yellow at base, tergites 5 to 8 entirely brown, all tergites narrowly bordered with black on lateral and hind margins, sternites yellowish brown; hypopygium yellow (Fig. 5). Hypopygium with tergite nine and sternite nine almost separated from each other, only fused at base (Figs 5, 9, 10, 12). Tergite nine U-shaped and emarginated at hind margin, densely covered with small black setae (Figs 10, 15); median area extended with pair of anal sclerites, between them with membranous area invisible from above, a few long yellow setae placed in the middle of this membranous area (Fig. 15). Appendage of gonocoxite bearing two parts: a big horn-shaped rod tapered to sharply acute and curved black apex, fringed with many long and yellow setae on lateral margin, and black bifurcated process originating from the base of the horn-shaped rod (Figs 5, 9, 10, 15, 16). Outer gonostylus small oval lobe, obtuse apically, tightly connected to base of inner gonostylus, bearing several long setae on outer margin (Figs 10, 11, 15, 16). Inner gonostylus, a fusiform lobe, with long setae on inner side, edged in black on both margins (Figs 12, 13, 15, 16). Sternite nine broader than tergite nine, deeply concave on posterior border (Fig. 16). Sternite eight shallowly concave on posterior border, medially with a group of long setae pointing caudally (Figs 5, 9, 15, 16). Genital bridge connected with base of gonocoxite, S-shaped, converged posteriorly into small common stem (Fig. 14). Aedeagal guide broad basally, narrowed apically, curved caudad, separated at apical half, with pair of lateral arms with inner margins expanded and variegated with black (Figs 9, 17, 18).

Semen pump. Compressor apodeme divided into two lobes by V-shaped notch, each lobe expanded apically with median ridge (Fig. 19). Posterior immovable apodeme with two arms elongated and curved dorsally (Figs 20, 21). Anterior immovable apodeme flattened and short, rounded in dorsal view (Figs 20, 21). Aedeagus elongated, tubular, thick basally, gradually narrowed to apex, more than 5.0 times longer than length of semen pump (Fig. 9).

Female.

Length: body 15.3 mm (not including antenna, n = 1); wing 15.4 mm (n = 1); antenna 2.5 mm (n = 1).

Coloration. General coloration of head, thorax, and abdomen similar to male.

Ovipositor. Yellowish brown in general. Sternite nine broad basally, acute apically; tergite nine broad, longer than tergite ten in lateral view (Fig. 22); sternite ten obtuse apically, densely covered with small setae, tergite ten broad at base, gradually narrowed to apex, the latter divided by suture (Figs 22, 25, 26). Cercus long, slight curved, widened at basal fourth, narrowed towards apex, slightly expanded apically, surpassing end of hypogynial valve (Figs 22, 25, 26). Hypogynial valve distinctly broader than cercus, rounded apically, broadened medially, bearing a black lobe on dorsal margin (Fig. 22).

Female internal reproductive system. Consisting of pair of accessory glands, bursa copulatrix, and three spermathecae with respective spermathecal duct (Fig. 27). Bursa copulatrix relatively elongate and narrow, rounded apically (Fig. 27). Accessory gland arising from base of bursa copulatrix, as pair of oval and swollen balls, terminating in small common stem (Fig. 27). Spermatheca spherical, black, bigger than the accessory gland (Fig. 27). Spermathecal duct slender, distinctly narrower than bursa copulatrix, flexible, generated from distal part of bursa copulatrix; connection points of three spermathecal ducts with bursa copulatrix not at same level (Fig. 27).

Distribution.

China (Guangxi).

Remarks.

The new species is generally similar to Tipulodina xyris (Alexander, 1949) by its colorations of the wing and legs ( Alexander 1949, Men et al. 2016). The new species can be separated from related species by the appendage of the gonocoxite possessing a basal horn-shaped rod and a bifurcate process (not present in T. xyris ), by the hind leg with basitarsus black on basal four fifths (hind leg with basitarsus black at basal third in T. xyris ), by the aedeagus more than 5.0 times longer than the length of semen pump (about 3.0 times longer than the length of its semen pump in T. xyris ) and by the shape of the aedeagal guide (Figs 9, 24). This new species also differs from T. xyris in organs of female internal reproductive system, including bigger spermathecae and accessary gland, and a narrower bursa copulatrix (Figs 27, 28).

Etymology.

The specific epithet is an adjective derived from the Latin furcata meaning forked, with the Latin prefix bi, referring to the presence of a bifurcate process on the appendage of the gonocoxite.