Dasyhelea alula Yu, 2005

Duan, Chen, Jiang, Xiao Hong, Chang, Qiong Qiong & Hou, Xiao Hui, 2019, First description of the immature stages of Dasyheleaalula and a redescription of adults from China (Diptera, Ceratopogonidae), ZooKeys 824, pp. 135-145 : 137-140

Dasyhelea alula Yu, 2005

Dasyhelea (Pseudoculicoides) alula Yu, 2005: 259 (male and female, China)

Material examined.

2 males, 3 females, 3 larvae, 3 larval exuviae, 2 male pupal exuviae, 3 female pupal exuviae. Xiaojiawan village, Xinpu new district, Zunyi city, Guizhou province, China, 27°43'22.83"N; 107°04'27.62"E, 7.VII.2018, alt. 866 m, Chen Duan leg.

Descriptions.

Fourth instar larva (Figs 1 a–c; 2 a–f). Head capsule yellowish, short, wide (Fig. 1a); HL 0.20-0.21 (0.20, n = 2) mm; HW 0.15-0.16 (0.15, n = 2) mm; HR 1.31-1.33 (1.32, n = 2); SGW 0.07-0.08 (0.08, n = 2) mm; SGR 0.47-0.50 (0.49, n = 2). Antenna short, cylindrical. Anterior portion of palatum (Figs 1a, 2a, b) with four pairs of campaniformia sensilla, posterior portion with three pairs of coeloconica sensilla, two simple, one serrate (Fig. 2a, c); messors well developed; scopae (Fig. 2a, c, d) well developed with more than 67 elongate, strong pointed teeth; maxilla (Fig. 2a) well sclerotized; mandible (Fig. 1a) stout, with three similar teeth, MDL 0.06 mm, MDW 0.02 mm; galeolacinia (Fig. 2a) with concentrated flap-like papillae, one seta; maxillary palpus (Fig. 2a, c) cylindrical, with 5-6 apical papillae; lacinial sclerite I with one short seta, dorsal view of lacinial sclerite I with three pairs of lobes; lacinial sclerite II without seta. Hypostoma (Fig. 2a) with mesal portion smooth, flanked with four strong, lanceolate lateral teeth on each side. Epipharynx (Fig. 1b) massive, strongly sclerotized, dorsal comb moderately wide, round, with 12 teeth, subequal elongate, lateral arms stout, elongate, with two auxiliary sclerites. LAW 0.08-0.13 (0.11, n = 3), DCW 0.03-0.04 (0.04, n = 3). Hypopharynx (Fig. 1c) stout, heavily sclerotized, posterior comb straight with fringe, with labium sclerotized. Thoracic pigmentation diffused, pale brown. Abdominal segments whitish, with diffused pale brown pigmentation. Caudal segment (Fig. 2e, f) with single comb, which has dense elongate and subequal teeth, with three long and stout crooked hooks.

Pupa (Figs 1 d–g; 3 f–k). Male. Total length 1.97 mm. General coloration of exuviae pale brown. Dorsal apotome (Fig. 1d) 2.7 × broader than long, triangular, with apex rounded, surface covered with brown rounded tubercles, anterior margin straight, lateral margin smooth, with three anterior wrinkles; apotome sensilla (Fig. 1d): DA-1-H elongate, thin seta, insert on well-developed tubercle, DA-2-H campaniform sensillum at base; disc surface covered by stout, rounded spinules; DAL 0.07 mm, DAW 0.19 mm, DAW/DAL 2.71. Respiratory organ, apex medium dark brown, 7.5 × longer than broad, with circular fold, 7-8 apical, three lateral pores; ROL 0.15 mm, ROW 0.02 mm; pedicel pale brown, short, length 0.01 mm, ROP/ROL 0.07. Mouthparts with mandible, lacinia absent; two clypeal/labrals (Fig. 3f), CL-1-H and CL-2-H both medium-sized and thin setae; two ocular sensilla, O-1-H long, thin seta, O-2-H campaniform sensillum (Fig. 3f); cephalothorax surface with small rounded tubercles, length 0.63 mm, width 0.45 mm; cephalothoracic sensilla as follows: three dorsolateral cephalic sclerite sensilla (Fig. 3g), DL-1-H and DL-2-H both medium- sized, thin setae, DL-3-H campaniform sensillum; three anterolateral sensilla (Fig. 3h), AL-1-T, AL-2-T both medium-sized, thin setae, AL-3-T short, stout seta; two anteromedial sensilla (Fig. 3h), AM-1-T medium-sized, thin seta, AM-2-T short, thin seta. Cephalothorax length 0.63 mm, width 0.45 mm. Cephalothoracic sensilla as follows (Fig. 3j): three dorsal setae (D-1-T, D-2-T, and D-3-T), D-1-T and D-2-T short, thin setae, D-3-T campaniform sensillum, SA-2-T supraalar campaniform sensillum. Metathoracic sensilla (Fig. 3i): M-2-T and M-3-T both campaniform sensilla. Abdomen: covered with short, stout spinules on anterior, posterior margin. Tergite I (Fig. 3i) with two depressions in the middle, setae as follows: D-2-I medium-sized, thin seta; D-4-I, D-7-I both campaniform sensilla; L-1-I long, thin seta. Segment IV (Fig. 3k) with sensillar pattern, as follows: D-2-IV short, stout seta; D-4-IV, D-7-IV both campaniform sensilla, D-8-IV short, stout seta, all located on flattened tubercles; L-1-IV long and stout setae, L-2-IV short, thin seta, L-3-IV short, thin seta, L-4-IV short, stout seta, all located on triangular tubercles; V-6-IV long, thin seta, V-7-IV short, stout seta, also located on flattened tubercles. Segment IX (Fig. 1e) 0.95 × longer than wide, length 0.19 mm, width 0.20 mm; ventral and dorsal surface with many spinules; terminal process triangular, elongated, acute, length 0.07 mm.

Female. Similar to male with usual sexual differences. Total length 1.64-1.75 (1.70, n = 2) mm. General coloration of exuviae pale brown, except dorsolateral cephalic sclerite brown. Dorsal apotome (Fig. 1f), DAL 0.08 mm, DAW 0.18 mm, DAW/DAL 2.25. Cephalothorax length 0.71 mm, width 0.42 mm. ROL 0.16-0.18 (0.17, n = 3) mm, ROW 0.02 (n = 3) mm; pedicel length 0.01 (n = 3) mm, ROP/ROL 0.11 -0.13 (0.12, n = 3). Segment IX (Fig. 1g) length 0.17-0.20 (0.19, n = 2) mm, width 0.20 (0.15, n = 2) mm; ventral surface with many spicules, single funnel-like structure medially. Terminal process (Fig. 1g) triangular, elongated, pointed, length 0.02-0.03 (0.02, n = 2) mm.

Redescription of adults (Figs 3 a–e; 4 a–k).

Male

(Figs 3 a–c; 4 a–e).

Head. Eyes (Fig. 4a) contiguous, abutting medially for length of 1.0 ommatidia, with interfacetal hairs. Antennal flagellum (Fig. 4b) brown, with distinct sculpture, sparsely plumose, flagellomere 13 without apical projection; AR 1.28. Frontal sclerite nearly round, with long, slender ventral projection (Fig. 4a). Clypeus (Fig. 4c) with four pairs of setae. Palpus (Fig. 4d) brown; third segment slender, the length almost the sum of the fourth and fifth segment. Lengths of palpus segments in ratio of 5: 8: 27: 12: 14.

Thorax. Scutum dark brown, scutellum yellow, with six stout setae. Legs brown; hind tibial comb with eight spines; foreleg TR 2.18, midleg TR 2.21, hind leg TR 2.33. Wing length 1.12 mm, width 0.33 mm, CR 0.40; wing membrane hyaline, densely covered with microtrichia, cubital fork at same level of distal portion of second radial cell.

Abdomen. Brown. Tergite IX nearly trapezoidal with prominent apicolateral processes. Posteromedial margin of sternite IX with elongate, slender projection, gonostylus slender (Figs 3a, 4e). Parameres fused, with median lobe short, thick, lateral lobe directly ventrolaterally (Figs 3b, 4e). Aedeagus complex, median process thick, long, its lateral processes each with curved apex (Figs 3c, 4e).

Female (Figs 3 d–e; 4 f–k).

Head. Eyes contiguous. Antennal flagellum (Fig. 4f) brown, without sculpture, flagellomere 13 without apical projection; AR 0.93. Frontal sclerite oval, with long, slender ventral projection (Fig. 4g). Clypeus (Fig. 4h) with seven pairs of setae. Palpus (Fig. 4i) brown; third segment slender, without capitate sensillae, lengths of palpus segments in ratio of 4: 7: 17: 7: 12.

Thorax. Hind tibial comb with seven spines; foreleg TR 2.00, midleg TR 2.14, hind leg TR 2.16. Wing length 0.82 mm, width 0.34 mm, CR 0.50 (Fig. 4j).

Abdomen. Similar to male. Subgenital plate (Figs 3d, 4k) flat, ring-shaped, posterolateral arms sclerotized into darker bands. Spermatheca round (Figs 3e, 4k), strongly pigmented, diameter 53.60 μm, neck short, stout, oblique, length 6.20 μm.

Distribution.

China (Guizhou province Fig. 5).