Ablabesmyia (Ablabesmyia) bifurca, 2019

Niitsuma, Hiromi & Tang, Hongqu, 2019, Taxonomic review of Ablabesmyia Johannsen (Diptera: Chironomidae: Tanypodinae) from Oriental China, with descriptions of six new species, Zootaxa 4564 (1), pp. 248-270 : 264-266

Ablabesmyia (Ablabesmyia) bifurca sp. n.

( Figure 9 )

Type material. Holotype male, CHINA: Guangdong Province, Guangzhou City, Conghua District, Lyutian Town , brook in Mt. Guifeng , 19.iv.2016 . Paratype: 1 male, as holotype except 28.ix.2015. Etymology. From the Latin bifurcus, bifurcate, referring to the form of the aedeagal blade in the male adult. Description. Male (n=2). Total length 3.6–3.8 mm. Coloration. Head brown; clypeus and palpomeres 1–3 dark brown, palpomeres 4–5 pale. Thorax dark brown, with pale pleural membrane. Abdomen mostly pale yellow; T I anteriorly brown; T VI–VIII entirely dark brown. Wing ( Fig. 9A ) with 2 dark spots at apices of R 1 and R 4+5; 2 middle spots present in cell m 1+2. Legs white with dark bands; sub-basal and median bands in foretibia located 0.73–0.76 and 0.39–0.43, respectively, from apex.

Head. Temporals 34–36. AR 1.7–1.8. Clypeus with 36–41 setae. Lengths of palpomeres 1–5 (µm): 60–65, 113– 115, 185–188, 228–245, 345–378. Palpomere 4 relatively long; Pm 4 /Pm 3 1.2–1.3, Pm 5 /Pm 4 1.5.

Thorax. Lateral antepronotals 27–28; acrostichals 64–70; dorsocentrals 39–40; humerals 19–20; prealars 34– 39; supraalars 1; scutellars 62–82.

Wing. Length from arculus to tip 1.8–2.0 mm. Squama with 35 (1) setae. VR 0.82–0.83.

Legs. Ti I spur 50–53 µm long, with 10–11 lateral teeth. Ti II spurs 63–65 and 48–50 µm long, with 8–10 and 7– 9 lateral teeth, respectively; inner spur/outer spur 1.3–1.4. Ti III spurs 70 and 50–53 µm long, with 8 (1) and 4–5 lateral teeth, respectively; inner spur/outer spur 1.3–1.4. Ti III comb consisting of 7 bristles. Lengths and proportions of legs as in Table 8.

Hypopygium ( Fig. 9B ). T IX with 2 setae on each side. Gonocoxite 175–180 µm long with weak basolateral bulge. Aedeagal complex ( Fig. 9C ) with dorsal lobe small, 20–23 µm long, bearing brush on lateral side; blade 68– 73 µm long, slightly curved, bifid with main branch digitiform and second branch tapered; lateral lobe apparently absent; lateral filaments not evident. Gonostylus 188–190 µm long, almost as long as gonocoxite.

Female, pupa and larva. Unknown.

Remarks. The male has two dark spots along the costal margin of the wing. The aedeagal complex is characterized by the apparent absence of lateral lobe, the presence of a brush on the dorsal lobe, and the aedeagal blade armed with a projection near the middle, which is not a basal projection as in A. (A.) monilis (Linnaeus) (see Niitsuma 2013). The bifid aedeagal blade is unique for this genus.

Within the genus Ablabesmyia , A. (A.) bifurca sp. n. and A. (Karelia) kisanganiensis Lehmann are exceptions in the adult with a palpomere 4 being longer than a palpomere 3. In most other species, the palpomere 4 is shorter than the palpomere 3 ( Roback 1971, Murray & Fittkau 1989).

Figures

FIGURE 9. Ablabesmyia (Ablabesmyia) bifurca sp. n., male. A, Wing; B, hypopygium, dorsal view; C, aedeagal complex.