Ablabesmyia (Ablabesmyia) pectinata, 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 : 259-261

Ablabesmyia (Ablabesmyia) pectinata sp. n.

( Figure 6 )

Type material. Holotype male with pupal exuviae, CHINA: Macau Special Administrative Region , Coloane Island, Hac-Sa Reservoir, 22°07.514'N, 113°34.232'E, 100 m alt., 1.xii.2014 (emerged 24.xii.2014) . Paratypes: 2 pupal exuviae, as holotype except mass rearing (adults emerged, lost 8.xii.2014); 1 male, as holotype except mass rearing (emerged 20.i.2015); 1 pupal exuviae, Guangdong Province, Guangzhou City, Conghua District, Lyutian Town , brook in Mt. Guifeng , 28.vi.2014; 1 male , Guangdong Province, Shantou City, Nan’ao County, Tsing’ao Reservoir , 26.viii.2016; 1 male , Guangxi Zhuang Autonomous Region, Baise City, Chengbi River , 26.vii.2015 .

Etymology. From the Latin pectinatus, comb-like, referring to the aedeagal lateral lobe with an apical row of teeth. Description. Male (n=4). Total length 2.6–3.1, 2.9 mm.

Coloration. Thorax brownish including scutal vittae, darker on anepisternum II, preepisternum and postnotum. Abdomen brown; T II–V each with dark anterior transverse band; T VI–VIII entirely darkened; hypopygium darkened on basolateral bulge of gonocoxite. Wing ( Fig. 6A ) with 2 dark spots at apices of R 1 and R 4+5. Legs white with dark bands; foretibia with sub-basal and median bands located 0.77–0.82, 0.79 and 0.34–0.38, 0.37, respectively, from apex.

Head. Temporals 25–35, 30. AR 1.6 (3). Clypeus with 39–46, 43 setae. Lengths of palpomeres 1–5 (µm): 35– 49, 46; 89–101, 97; 108–138, 127; 101–128, 116; 209–295, 258 (3). Pm 4 /Pm 3 0.89–0.93, 0.92; Pm 5 /Pm 4 2.1–2.4, 2.3 (3).

Thorax. Lateral antepronotals 12–15, 13; acrostichals 63–92 (2); dorsocentrals 24–30, 27; humerals 14–22, 19; prealars 15–23, 19; supraalars 1 (3); scutellars 37–39, 38.

Wing. Length 1.7–2.0, 1.9 mm. Squama with 31–36, 34 (3) setae. VR 0.84–0.88, 0.86.

Legs. Ti I spur 40–45, 43 µm long, with 7–9, 8 lateral teeth. Ti II spurs 50–60, 55 and 28–33, 31 µm long, with 6–8, 7 and 5–7, 6 lateral teeth, respectively; inner spur/outer spur 1.6–2.2, 1.8. Ti III spurs 60–71, 65 and 28–35, 32 µm long, with 4–6, 5 (3) and 3–4, 4 (3) lateral teeth, respectively; inner spur/outer spur 1.9–2.3, 2.0. Ti III comb consisting of 4–6, 5 bristles. Lengths and proportions of legs as in Table 5.

Hypopygium ( Fig. 6B ). T IX with 2–4, 3 setae on each side. Gonocoxite 125–165, 153 µm long, with strong basolateral bulge. Aedeagal complex ( Fig. 6C ) with dorsal lobe 31–38, 33 µm long, bare, beak-shaped in dorsal view; blade 38–44, 42 µm long, gently curved dorsally, tapering toward pointed apex; lateral lobe 70–78, 74 µm long, 1.7–2.0, 1.8 times as long as blade, apically membranous with teeth; lateral filaments not evident. Gonostylus 134–175, 162 µm long, and almost as long as gonocoxite.

Pupa (n=4). Body length 3.5–4.6, 4.0 mm.

Coloration. Exuviae pale brown. Wing sheath infuscated along margin and veins ending before margin. Abdomen uniformly brown, occasionally T II–VIII ( Fig. 4D ) with slightly darkened anteromedial patch.

Cephalothorax. Thoracic horn ( Fig. 6E ) bulbous, 294–353, 323 (3) µm long and 2.1–2.6, 2.3 (3) times as long as broadest width; apical nipple ( Fig. 6F ) evident, with aeropyle tube club-shaped apically. Thoracic comb with 9– 12, 11 teeth.

Abdomen ( Fig. 6G ). Tergal shagreen ( Fig. 6H ) sparse, consisting of solitary spinules 2–3 µm long; several anterolateral spinules tending to arrange in slightly arched rows. LS 1 -seta on A VII located 0.45–0.49, 0.47 from anterior margin, and on A VIII located 0.24–0.29, 0 27. Anal lobe 304–400, 366 µm long, 2.1–2.6, 2.4 times as long as wide, with anterior and posterior macrosetae located 0.46–0.55, 0.52 and 0.56–0.64, 0.61, respectively, from anterior margin; outer margin spinulate. Male genital sac 0.79 (1) times as long as anal lobe.

Female and larva. Unknown.

Remarks. The male is similar to that of A. (A.) janta (Roback) in possessing a slightly curved aedeagal blade with a pointed apex and the elongated lateral lobe with apical teeth, but distinct in the beak-shaped dorsal lobe and the much longer lateral lobe, which is twice as long as the aedeagal blade. In A. (A.) janta, the dorsal lobe is straight in dorsal view and the lateral lobe is at most 1.5 times as long as the blade ( Roback 1971, 1985). The pupa is also separable from that of A. (A.) janta by the abdominal pigmentation pattern, which is entirely brown, occasionally darker anteromedially. In A. (A.) janta, the abdominal tergite IV has a pair of dark vertical bands ( Roback 1985, fig. 228). In addition, the pupa of this new species is armed with sparse shagreenation consisting of solitary spinules on the abdominal tergites. The typical pupa of Ablabesmyia s. str., has tergal shagreenation composed of arched rows of 2–3 scales ( Roback 1985, Fittkau & Murray 1986). In the pupal shagreen, A. (A.) pectinata sp. n. resembles A. (A.) rimae Harrison , too. Although the pupal description of the latter is incomplete, both the species are easily separated using the adult male hypopygium, specifically the aedeagal complex. The male of A. (A.) pectinata sp. n. possesses a beak-shaped dorsal lobe and a long lateral lobe with apical teeth, while that of A. (A.) rimae has a dorsal lobe with two apical projections and lacks a distinct lateral lobe ( Harrison 1991).

Figures

FIGURE 4. Ablabesmyia (Ablabesmyia) maculitibialis Chaudhuri, Debnath et Nandi, male. A, Wing; B, femora and tibiae of P 1–3, showing pigmentation pattern; C, hypopygium, dorsal view; D, aedeagal complex. l/L, Relative position of tibial apicalmedian band of P 3.

FIGURE 6. Ablabesmyia (Ablabesmyia) pectinata sp. n., male (A–C) and pupa (D–H). A, Wing; B, hypopygium, dorsal view; C, aedeagal complex; D, abdominal segment IV, dorsal view, showing pigmentation pattern; E, thoracic horn; F, apex of thoracic horn, showing details of apical nipple; G, abdomen, dorsal view; H, shagreen on posteromedial part of abdominal tergite IV.