Polypedilum (Tripodura) procerum, Zhang, Ruilei, Song, Chao, Wang, Liqing & Wang, Xinhua, 2015

Zhang, Ruilei, Song, Chao, Wang, Liqing & Wang, Xinhua, 2015, Two new species of the acifer species group of Polypedilum subgenus Tripodura Townes from China (Diptera: Chironomidae), Zootaxa 3918 (4), pp. 571-578 : 575-577

Polypedilum (Tripodura) procerum sp. n.

( Figs 2A–D )

Type material. Holotype (BDN. 21333): male. CHINA, Guangdong Province, Fengkai County, Heishiding Natural Conservation, 12. IV. 1985, light trap, X. Wang. Paratypes: 2 males. 1 male as holotype. 1 male: Fujian Province, Fuzhou City, on campus of Fuzhou Agricultural College, 22. IV. 1993, light trap, X. Wang.

Etymology. The species name is from Latin “ procerus ”, means slender, referring to the thin and slender superior volsella.

Diagnostic characters. P. (T.) procerum sp.n. can be separated from other related species by the following characters: tergite IX subcircular; anal tergite bands very short, gradually narrowed, abruptly terminating at the base of tergite IX; superior volsella S-like, bare and very long, with a hooked apex; inferior volsella slender, uniformly elongated.

Description. Male imago. (n =3)

Total length 2.03–2.43 mm. Wing length 1.08–1.46 mm. Total length/ wing length 1.57–2.05. Wing length / length of profemur 2.28–2.43.

Coloration. Head brown with yellow palpomeres. Thorax brown with darker vittae, postnotum and preepisternum. Abdominal segments entirely yellowish brown. Legs yellowish brown.

Head. AR 0.86–1.24. Ultimate flagellomere 326–494 µm long. Temporal setae 6–8. Clypeus with 8–12 setae. Tentorium 88–90 µm long, 21–23 µm wide. Palpomere lengths (in µm): 26–29, 26–29, 70–81, 73–104, 112–140.

Wing ( Fig. 2A ). VR 1.22–1.51. R with 13–18 setae; R1 with 8–9; R4+5 with 11–16. Squama with 4–5 setae.

Thorax. Dorsocentrals 7–9, acrostichals 9–15, prealars 2–3. Scutellum with 3–4 setae.

Legs. Terminal scale ( Fig. 2B ) of front tibia 31–39 µm long, triangular and apically pointed; spur of median tibiae 31–34 um long including 16–18 µm long comb, un-spurred comb 16–17 µm long, spur of posterior tibia 36–42 µm long including 16–18 µm long comb, un-spurred comb 16–23 µm long. Width at apex of front tibia 31–36 µm, of middle tibia 31–39 µm, of hind tibia 36–47 µm. Lengths (in m) and proportions of legs as in Table 3 .

Hypopygium ( Figs. 2C–D .). Tergite IX subcircular; anal tergite bands very short, gradually narrowed, interrupted at a long distance from the basal area of anal point. Anal point 40–50 µm long, broad and apically rounded; the lateral projections weak, about 5–8 µm long; dorsally with a V-shaped ridge bearing 5–6 setae on each side. Superior volsella ( Fig. 2C ) S-shaped, pointed apically, with a hooked apex, nearly reaching apex of anal point and distal part of inferior volsella. Inferior volsella 95–105 µm long, slender, uniformly elongated, curved inwards on its proximal half, distal half straight and uniformly elongated, dorsally with 4–5 orally projected setae, 1 longer apical seta present apically. Gonocoxite 81–107 µm long. Gonostylus 109–138 µm long, narrow at about basal 1/4, medially expanded and gradually narrowed towards apex, with 6 long setae along inner margin. HR 0.71–0.78, HV 1.66–2.23.

Distribution. The new species was collected from Fujian and Guangdong Provinces (Oriental China).

Remarks. The new species is very close to P. (T.) leptovolsellae Ree, 2009 and P. (T.) pseudacifer Zorina & Makarchenko, 2001 , in having a long, extremely slender and apically curved superior volsella. The differences between the three species are given in Table 4 .

procerum sp. n. leptovolsellae pseudacifer Fore leg ration 2.30–2.33 1.88 1.88–1.93

1. Tergite IX without lateral projections...................................................................... 2

- Tergite IX with lateral projections or conspicuous shoulders.................................................... 6

2. Anal point slender and parallel-sided................................................. P. (T.) masudai (Tokunaga)

- Anal point broad or apically expanded..................................................................... 3

3. Superior volsella spatula-shaped and inferior volsella with less than 5 setae................ P. (T.) spathum Zhang & Wang

- Superior volsella pad-like and inferior volsella with more than 10 setae........................................... 4

4. Terminal scale of fore tibia pointed, distal margin of superior volsella with 2–3 setae, anal point broad, distal part of r4+5 clear.............................................................................. P. (T.) japonicum (Tokunaga)

- Terminal scale of fore tibia rounded, distal margin of superior volsella with more than 19 setae, anal point spatula-shaped api- cally, distal part of r4+5 cloudy............................................................................ 5

5. Anal point with 6 setae at base, superior volsella goblet-shaped; gonostylus slender and apex narrowed................................................................................................... P. (T.) cypellum Qi et. al.

- Anal point with 2 rows of short dorsal setae, each row with 8−10 setae; superior volsella pediform; gonostylus moderately broad, apex not narrowed................................................... - P. (T.) harteni Andersen & Mendes

6. Wing without markings............................................................... P. (T.) procerum sp. n.

- Wing with markings, usually boldly marked with several dark spots and clouds, sometimes faint and restricted in a few areas.................................................................................................... 7

7. Wing marking faint, without spot in cell r4+5................................................ P. (T.) falcatum sp. n.

- Wing marking distinct, with more than 1 spot in cell r4+5....................................................... 8

8. Fore tibial scale rounded apically.................................................... P. (T.) scalaenum (Schrank)

- Fore tibial scale pointed apically......................................................................... 9

9. Lateral projections of anal point strongly sclerotized and without microtrichiae........ P. (T.) nudiprostatum Zhang & Wang

- Lateral projections of anal point covered with microtrichiae................................................... 10

10. Wing with 3 dark spots in cell r4+5........................................... P. (T.) decematoguttatum (Tokunaga)

- Wing with 2 dark spots in cell r4+5........................................................................ 11

11. Superior volsella clavate with 2 strong spines directed medially in inner margin........... P. (T.) bispinum Zhang & Wang

- Superior volsella pad-like with more than 5 setae directed posteriorly................. P. (T.) cochlearum Zhang & Wang

Figures

FIGURES 2 A – D. Polypedilum (Tripodura) procerum sp. n. A. Wing. B. Fore tibial scale. C. Superior volsella. D. Hypopygium, dorsal and ventral view.

Tables

TABLE 3. Lengths (in Μm) and proportions of legs of species P. (T.) procerum sp. n., male.

PI	PII	PIII
fe 473–599	557–693	609–746
ti 252–315	410–504	483–620
ta1 588–725	242–292	336–431
ta2 368–468	133–164	180–239
ta3 263–336	85–106	159–207
ta4 210–263	23–58	90–117
ta5 95–126	42–53	58–64
LR 2.30–2.33	0.58–0.59	0.70–0.71

TABLE 4. Main distinguishing characters between P. (T.) procerum sp. n., P. (T.) leptovolsellae Ree and P. (T.) pseudacifer Zorina & Makarchenko.

Spur on scale of fore tibiae	Absent	Present	Present
Length of anal point	40–50µm	63µm	unknown
Dorsal base of anal point	Having a V-shaped ridge	Having a mulberry shaped protuberance	Having a v-shaped ridge
Shape of superior volsella	S-shaped	S-shaped	Hook-like
Short setae on apical inner margin of superior volsella	Absent	Present	Present
Key to known male imagines	of Polypedilum subgenus	Tripodura from China