Oriental Chironomus: C. "orientalis" adult

**"Chironomus flaviplumus"**

This species is related to C. flaviplumus in Japan, but a new name is needed for this species (Martin 2011b), so C. orientalis is suggested.

In Bold bin: BOLD:AAV5954.

Adults:

Adult from Queensland (photo by Graeme V. Cocks)

Males:

C. flaviplumus type 3: Male hypopygium (left) and superior volsella (right) (note beaked shape)

AR about 2.4 - 2.9 (Specimens from Japan have an AR of 3.5-4.0, and probably should be considered as C. flaviplumus - see also under "Cytology")
Frontal tubercles about 33 - 39 µm, and about 3 times longer than wide.
Palp proportions (micron): 44 : 53 : 189 : 222 : 315
Wing length: 2.85 - 3.15 mm; wing width 0.30 - 0.67 mm. VR about 1.02-1.07; abt 2-4 SCf on brachiolum; 9-14 setae in squamal fringe.
Thoracic setae - achrostichal about 12-18; dorsocentral about 13-18; prealar about 4-6; supra alar 1; scutellar in 2 approximate rows, 6-7 in anterior row, 11-17 in posterior row.

Legs pale, lengths (micron) and proportions as follows:

	Fe	Ti	Ta1	Ta2	Ta3
PI	1350	975	1820	925	837
PII	1305	1155	750	393	268
PIII	1478	1385	1180	595	448
	Ta4	Ta5	LR	F/T	BR
PI	712	362	1.82-1.96	1.35-1.44	1.7-2.2
PII	168	125	0.62-0.67	1.11-1.17
PIII	262	152	0.81-0.92	1.05-1.09

Abdomen pale (greenish) with a relatively broad brown band about the middle of segments II-V, then covering most of the following segments.
The superior volsella is essentially a D(e)-type of Strenzke (1959), although often of a beaked type not illustrated by Strenzke (1959), i.e. it varies between a D- and an almost S-type.
Setae on 9th tergite: 9 - 12; some setae on inferior volsellae with a simple or trifid fork; gonostylus reduces fairly quickly over posterior half.

Female:
Wing length 3.28 - 3.53 mm; width at cross vein 0.83 - 0.90 mm, VR 1.08-1.21.$nbsp;$nbsp;About 2-4 SCf on brachiolum; 17-22 setae in squamal fringe.
Head with frontal tubercles about 14 �m long and 13 �m wide; about 27 - 55 clypeal setae.
Antennal segments (microns): 190 : 127 : 147 : 121 : 215.$nbsp;$nbsp;AR about 0.36; A5/A1 about 1.13.
Thoracic setae - acrostichal about 13-17; dorsolateral about 32-44; prealar about5; supra alar 1; scutellar in two approximate rows, 5 in anterior row; 11 in posterior row.

Leg proportions (micron)

	Fe	Ti	Ta1	Ta2	Ta3
PI	1664	1196	2290	1255	1189
PII	1588	1410	845	452	313
PIII	1727	1663	1338	706	557
	Ta4	Ta5	LR	F/T	BR
PI	1189	405	1.91-1.92	1.37-1.42	1.44-1.82
PII	196	152	0.58-0.61	1.11-1.14	-
PIII	317	190	0.79-0.82	1.02-1.06	-

ant Ta4/Ti about 0.98; Ta3 and Ta4 subequal in length.

Abdomen pale (probably greenish); about 4 setae on gonopophysis VIII.

Differences from other members of the C. samoensis/flaviplumus group:
Important features of males are the AR of 2.4-2.9 (lower than that of C. flaviplumus, but similar to C. samoensis), LR of about 1.8 - 2.0 and fore Ta5, which is about 0.35 - 0.4 length of Ti. In Australia, it is the only presently known species with a beaked superior volsella.
In the female the fore legs are very long, with LR about 1.9, and Ta3 and Ta4 are about equal in length, only a little shorter than Ta2, ratio Ta4/Ti about 0.98
See here for descriptions of C. samoensis Edwards.
The Australian species is probably most closely related to the Japanese C. flaviplumus Tokunaga.

Molecular Sequence:
CO1 - GenBank accession nos. for Chinese specimens are KP902730 & -31. and for Thailand KT213029-038. In BOLD they have 99.5% similarity to an early release sequence named as ChironomidaeGC sp. 7 from Queensland, Australia.

Found: Northern Territory - Radon Creek, Kakadu National Park; (12.75°S, 132.93°E); Twin Falls, off Jim Jim Road, Kakadu area
(13.00°S, 132.58°E).
Queensland - 3 km w. Sarina Beach (21.40°S, 149.25°E).
The species is also widespread in the Orient.

Indian specimens described by Chattopadhyuy et al. (1991), are not the same species and one has been renamed C. indiaensis (Martin 2011b), while others are the widespread species PK2.

Australian adults of this species can be bred in the laboratory, as fertile egg masses were obtained from adults reared from wild collected larvae. The related Japanese species has also been maintained in a laboratory culture (Elbetieha & Kalthoff 1988).

[ Return to Index | Go to C. flaviplumus type 3 immatures ]