Polypedilum (Cerobregma) heberti Lin et Wang, 2019

Lin, Xiao-Long, Yu, Hai-Jun, Zhang, Rui-Lei & Wang, Xin-Hua, 2019, Polypedilum (Cerobregma) heberti sp. n. (Diptera: Chironomidae) from Gaoligong Mountains, Yunnan, China, Zootaxa 4571 (2), pp. 255-262 : 256-258

Polypedilum (Cerobregma) heberti Lin et Wang sp. n.

( Figs 2–5 )

Type material. Holotype: male ( BDN & BOLD sample ID: XL821), China, Yunnan Province, Baoshan City, Longyang District, Mangkuan Ethnic Town , Gaoligongshan National Nature Reserve , Baihualing , near the beauty waterfall, 25.303056°N, 98.8011111°E, 1536 m a.s.l., 23.V.2018, sweep net, X.L. Lin.

Etymology. Named after Prof. Paul D. N. Hebert, the father of DNA barcoding; noun in genitive case.

Diagnostic characters. The adult male of the new species keys to the Polypedilum (Cerobregma) morphologically, and can be distinguished from known species of the subgenus Cerobregma by the following combination of characters: body mostly with darker scutal stripes, postnotum, epimeron II, median anepisternum II and preepisternum; tergite II–VI brown with horizontal dark brown bands at middle, remaining largely dark brown; most of femur and tibiae dark brown, distal 1/3 of femur pale brown; all tarsomeres yellow; AR 0.51; wing pale with a black spot on the basal half area of wing; LR 1 1.02; antepronotum bare; anal tergite with 30 median setae; superior volsella with five inner basal setae, without outer seta; seta along inner margin of gonostylus not split.

Adult male (n = 1). Total length 4.20 mm. Wing length 2.83 mm. Total length/wing length 1.48. Wing length/ length of profemur 1.88.

Coloration ( Figs 2–3 ). Head brown with dark brown palpomeres. Antenna yellow. Thorax ground colour brown with dark brown stripes on scutum, laterally under parapsidal suture, postnotum and on preepisternum; dark brown median anepisternum II, epimeron II. Tergite II–VI brown with horizontal dark brown bands at middle; tergite I, VII–VIII and hypopygium largely dark brown. Most of femur and tibiae dark brown, distal 1/3 of femur pale brown; all tarsomeres yellow. Wing pale brown with a large black spot on the entire basal half area of wing.

Head ( Fig. 3A ). Antenna with 13 flagellomeres; ultimate flagellomere 365 mm long; AR 0.51. Temporal setae 18, including 8 inner verticals, and 10 outer verticals. Clypeus with 46 setae. Tentorium 150 mm long; 35 mm wide. Stipes 163 mm long, 23 mm wide. Lengths of palpomere 1–5 (in m): 75, 75, 188, 153, 215. Palpomere ratio (5 th /3 rd) 1.14.

Thorax ( Fig. 3B ). Acrostichals 8; humerals 5; dorsocentrals 20; prealars 15. Scutellum with 60 setae. Haltere with nine setae.

Wing ( Fig. 3C ). VR 1.26. Brachiolum with eight setae; R with 33 setae; R 1 with 34 setae; R 4+5 with 40 setae; M with one seta; RM with three setae; remaining veins bare. R 2+3 distinct. Squama with 17 setae.

Legs. Terminal scale of fore tibia broken; spur of mid tibia 80 mm long including 45 mm long comb, unspurred comb 43 mm long; spur of hind tibia 83 mm long including 57 mm long comb, un-spurred comb 48 mm long. Apical width of fore tibia 75 mm; of mid tibia 90 mm; of hind tibia 95 mm. Lengths (in mm) and proportions of legs as in Table 2.

Hypopygium ( Figs 4–5 ). Anal tergite with 30 median setae. Laterosternite IX with nine setae. Anal point strong, tapering, 113 mm long. Transverse sternapodeme 50 mm long; phallapodeme 175 mm long. Gonocoxite 260 mm long. Superior volsella 143 mm long; with basal microtrichia and five inner setae ( Fig. 5C ). Inferior volsella 225 mm long, finger-shape, divided into two lobes apically, with 22 long setae. Gonostylus 243 mm long. HR 1.07; HV 1.73.

Female and immatures unknown.

Remarks: It is unique in this new species, within the subgenus Cerobregma , the wing with a large black spot on the entire basal half area. The morphology of hypopygium of the new species resembles P. exilicaudatum Saether et Sundal. The main differences between new species and P. exilicaudatum are listed in Table 3.

Figures

FIGURE 2. Polypedilum (Cerobregma) heberti sp. n., holotype male in alcohol.

FIGURE 3. Polypedilum (Cerobregma) heberti sp. n., holotype male. A. head; B. thorax; C. wing. Scale bar = 100 µm.

FIGURE 4. Polypedilum (Cerobregma) heberti sp. n., holotype male. A. hypopygium dorsal view; B. hypopygium ventral view. Scale bar = 100 µm.

FIGURE 5. Polypedilum (Cerobregma) heberti sp. n., holotype male. A. hypopygium dorsal view; B. hypopygium ventral view; C. superior volsella.