A new record and two new species of Cryptochironomus Kieffer, 1918 from China (Diptera, Chironomidae)
Author
Yan, Chuncai
Author
Zhao, Guangjun
Author
Liu, Ting
Author
Guo, Qin
Author
Hou, Ziyuan
Author
Wang, Xinhua
Author
Pan, Baoping
text
Zootaxa
2016
4208
5
485
493
journal article
37390
10.11646/zootaxa.4208.5.6
2887a8ec-aa03-4000-a5f9-5d4cb2e2cffa
1175-5326
211867
8713233F-4AC8-4926-BD16-857A6B48FF27
Cryptochironomus protuberans
Yan & Wang
sp. n.
(
Figs. 3
A–E)
Type
material.
Holotype
:
1 ♂
(BDN No. 27124),
China
,
Xinjiang Uygur
Autonomous Region,
Yining County
,
Sayram Lake
,
27°31′11″N
,
106°54′00″E
,
30. vii. 2002
,
sweeping net
,
H. Q. Tang
. 2 Paratypes: 2 ♂♂ (BDN No. 27126, 27140), data as holotype.
Diagnosis.
All legs dark brown. Posterior margin of tergite IX with long pointed projection on each side. Anal point slender, and tapered towards the apex. Superior volsella triangular with microtrichia except basal part. Anal tergite bands V-shaped. Gonostylus fused with gonocoxite, widened at apex.
Description.
Male imago (n = 3, unless otherwise stated).
Total length
7.55–8.50 mm
; wing length 4.00–
4.65 mm
; total length / wing length 1.83–1.89; wing length / length of profemur 3.03–3.32.
Coloration
. Thorax yellow brown, with dark brown spots. All legs dark brown. Abdominal tergites brown, hypopygium dark brown.
Head
. Antenna with 11 flagellomeres. AR: 2.58–2.78. Ultimate flagellomere
820–900 mm
. Frontal tubercles (
Fig. 3
A) column, 50 (2) mm high, 30–33 (2) mm wide at basal. Temporal setae 23 (2), including 6 (2) inner verticals; 10 (2) outer verticals; and 7 (1) postorbitals. Clypeus with 18–20 setae. Tentorium 213–255 (2) mm long, 75–82 (2) mm wide. Palpomere lengths (µm): 58, 115; 215; 190; 273 (1); palp segment 5th / 3rd: 1.27 (1).
Thorax
. Antepronotum with 4–6 setae, acrostichals 14, dorsocentrals 24–26, prealars 6 (1). Scutellum with 32 setae (1).
Wing
(
Fig. 3
C). VR: 1.04–1.12. R with 22–24 setae. R1 with 16–19 setae. R4+5 with 16–21 setae. Brachiolum with 2–3 setae. Squama with 12–15 fringed setae. Anal lobe developed.
Legs
. Front tibia with 3 subapical setae,
125–152 mm
,
130–148 mm
and
140–158 mm
long. Mid leg with 2 tibial spurs,
30–35 mm
and
35–43 mm
long, ta1 with 6 sensilla chaeticae, comb with 34–40 teeth,
10–15 mm
long. Hind leg with 2 tibial spurs,
30–36 mm
and
45–55 mm
long, ta1 with 1 sensilla chaeticae, comb with 52–60 teeth,
12–18 mm
long. Lengths (in µm) and proportions of thoracic legs as in
Table 2
.
TABLE 2.
Lengths (in µm) and proportions of adult male legs in
C. protuberans
Yan & Wang
sp. n.
(n=3).
P1 |
P2 |
P3 |
fe |
1320–1400 |
1420–1510 |
1500–1700 |
ti |
1300–1380 |
1370–1480 |
1400–1850 |
ta1 |
1470–1600 |
690–770 |
940–1030 |
ta2 |
750–770 |
320–410 |
330–410 |
ta3 |
700–840 |
280–350 |
270–320 |
ta4 |
570–630 |
250–310 |
180–200 |
ta5 |
280–310 |
210–240 |
100–130 |
LR |
1.13–1.16 |
0.50–0.52 |
0.56–0.63 |
Hypopygium
(
Figs. 3
B, D–E). Posterior margin of tergite IX with long pointed projection on each side, bearing 22–28 setae at base of anal point. Laterosternite IX with 6 setae. Anal point
195–220 mm
long, slender, tapered towards the apex. Superior volsella triangular, with 6 long setae apically, with microtrichia except basal part. Inferior volsella (
Fig. 3
B, E) small, completely covered by superior volsella, with 5 long setae, without microtrichia. Anal tergite bands V-shaped. Phallapodeme
150–230 mm
long. Transverse sternapodeme
140–180 mm
long. Gonocoxite
180–265 mm
long, bearing 5–7 strong setae along inner margin. Gonostylus
280–310 mm
long, with 20–24 short setae along inner margin, fused with gonocoxite, swell at apex. HR: 0.64–0.85; HV: 2.44– 3.04.
FIGURE 3.
Cryptochironomus protuberans
Yan & Wang
sp. n.
, male. A—frontal tubercles; B—inferior volsella; C—wing; D—hypopygium (dorsal view); E—hypopygium (ventral view).
Etymology.
The specific name is from Latin
protubero
, meaning ‘swell or bulge out’, and suffixes ‘–
ans
’ referring to tergite IX distal with long pointed projection distally on each side.
Remarks.
The male of
C
.
protuberans
Yan & Wang
sp. n.
can be separated from other
Cryptochironomus
species basing on unusual long pointed projection on each side of tergite IX together with gonostylus fused with gonocoxite, swell at the apex.
The new species resembles
C. stylifera
(
Johannsen, 1908
)
in the gonostylus fused with gonocoxite, swell at apex together with the shape of superior volsella and inferior volsella. But the new species can be separated from latter species on the basis of following characters: (1) the AR of the new species (2.58–2.78) is much lower than that of
C. stylifera
(4.35–5.12); (2) the long pointed projection at each side of tergite IX of new species is sufficient to distinguish it from
C. stylifera
. Moreover, the new species is also close related to
C
.
jokaprimus
Sasa & Ogata, 1999
by the similar anal point (slender, tapered towards the apex) and low AR. However, the superior volsella of the new species is triangular, and inferior volsella is small, whereas
C
.
jokaprimus
has a bulbous-like superior volsella and a digital inferior volsella. Also, the body size of
C
.
jokaprimus
(
4.73 mm
) is much smaller than that of new species (
7.55–8.50 mm
), and the gonostylus of
C
.
jokaprimus
is without typical distinctly broadened apex.
Female and immature stages unknown.