C. vitellinus Freeman 1961

Male:
A yellowish-green species with dark bands on the tarsi and darkening of the cross veins of the wings.  Thorax of a yolky colour, dull with practically no pruinosity; legs whitish especially on tibiae, tarsal segments black at joints; abdomen without dark markings but quite strongly pruinose at incisures and on segments 5 and 7, anal point of male narrow at base in side view.

Photograph of adult male (G. Cocks, Townsville)(left) and Illustration of the hypopygium of C. vitellinus from Tokunaga 1964 (right)

Wing length 2.64 (2.07-3.00) mm, width 0.64 (0.56-0.73) mm; VR 1.05 (1.02-1.08); 2 Scf on brachiolum, 19.5 (17-22) setae on squamal fringe.
Freeman (1961) quotes AR about 4.5, but in other populations the AR is lower 3.34 (2.89-4.5)  
Head:  Frontal tubercles 43.7 (30-55) µm long and 2.4-3.7 times longer than wide.  Palpal proportions (micron): 49 : 46 : 157.5 : 191 : 272 : P5/P4 1.45 (1.25-1.74); P5/P3 1.79 (1.40-2.17).  Clypeus about 0.60 (0.47-0.75) of antennal pedicel, with about 18.2 (11-23) setae.
Thoracic setae: acrostichal from about 4-11; dorsocentrals 9.7 (5-14); Prealar 4.25 (3-5); Supraalar 1; Scutellar 10.75 (13-17), 2-6 in anterior row, 5-11 in posterior row.
Leg lengths (microns) and proportions as follows:

Male	Fe	Ti	Ta1	Ta2	Ta3	Ta4	Ta5	LR	F/T	BR
PI	1245	970	1480	895	715	740	340	1.56-1.93	1.11-1.27	0.46-1.6
PII	1215	1085	715	370	270	180	135	0.64-0.70	1.10-1.17
PIII	1325	1345	1075	575	425	270	165	0.77-0.83	0.95-1.00

Pupa:  has been illustrated by P.S. Cranston in his Electronic Guide to Chironomidae of Australia.  This illustration is reproduced (with permission) (below).
Length: Male 6.40 (6.38-6.70) mm; female 7.01 (6.90-7.14) mm.  Exuviae grey.  Cephalic tubercles 86.3 (81-110) µm long and 56.5 (51-70) µm in diameter, subapical seta 56 (38-90) µm long, i.e. about as long as the tubercles.  There is slight development of frontal warts (see Cranston figure) - abt. 38 x 6 µm.  Respiratory base about 132.7 (119-157) x 62.25 (51-81) µm wide.  2 pairs of precorneal setae.
Abdomen with Pedes spurii A caudolateral on segments IV-VI, that on segment IV about 145 (116-157) x 89 (71-111) µm wide and about 22 (18-24)% of the segment length; Pedes spurii B basolateral on segment I and small caudolateral on segment II, which also bears a caudal row of about 66.2 (54-81) hooks which occupy 58-68% of the segment width.  Caudolateral spur of segment VIII usually with 1-4 spines, although commonly only 1 is long.  Swim fin with about 70.3 (61-78) taeniae in a single row proximally and a double row distally.

Fourth instar larva: a medium sized, essentially plumosus-type larva, although lateral tubules (656 (520-800) µm long) are more ventrally placed than in other species.  Length 11.5(10.5-12.5 mm (female), 9.75 (9-10.5 mm) (male) and ventral tubules long, anterior pair 1.84 (1.32-1.84) µm generally longer than posterior pair 1.62 (0.96-2.16) µm.  Anal tubules with median constriction, about 550 (500-600) micron long, and 3.57 times longer than wide; ventral 430 (420-440) µm long and 3.67 times longer than wide.  Salivary reservoir (1 specimen) 86 x 15 ݙm (5.4 times wider than deep.
Gula pale or slightly darkened on posterior third, slightly wider than mentum width and widest at the posterior margin;  frontoclypeus pale.
Mentum (Fig. c) with the central trifid tooth set below the 1st laterals, and the c2 teeth markedly separated from c1 tooth (type IIA) and pointed towards it; 4th laterals at most slightly reduced (type I).
Pecten epipharyngis (Fig. a) with about 14 (12-16) often irregular teeth (type D).  Ventromentum (Fig. d) about 3.8 times wider than deep; separated by about 0.36 of the mentum width, with about 31 (27-32) striae.
Antenna (Fig. b) with the basal segment about 3.5 times as long as wide; AR about 2.65 (2.47-2.83); ratio of segments 116.5 : 25 : 5.5 : 8 : 5.
Distance between S4 setae (142 µm) slightly larger than width between antennal bases (121 µm).  S5 setae about level with nearby RO.
Mandible (Fig. e) about 207 (199-215) µm long, with third inner tooth darkened and completely separated (type IIIB), with three spines on inner margin, and about 11-12 furrows on the outer surface at the base; Mdt/Mat about 24, MTR 0.38 (0.32-0.48).

The larva is most readily recognised by the unusual premandible, which has 7 teeth (as opposed to C. javanus which has only 6) rather than the usual two, as well as the lowered central trifid tooth of the mentum.

Some larval characters have been illustrated by P.S. Cranston in his Electronic Guide to Chironomidae of Australia, as C. vitellinus.  These are reproduced here (with permission).

Cytology:  4 polytene chromosomes chromosomes possibly with the thummi arm combination AB, CD, EF, G, but Keyl arms very difficult to recognize.
Nucleolus virtually terminal in arm G, with large Balbiani Ring near middle of the arm; closely paired.  No nucleolus in long chromosomes.

Found: Type locality Northern Territory - Darwin.
            New South Wales - Manning River, Kundibakh, (paratype).
            Queensland - Mareeba (-16.98°S, 145.42°E); Sarina (-21.42°S, 149.20°E); 3 km w. Sarina Beach (-21.42°S, 149.20°E);
            Townsville (-19.25°S, 148.78°E).
            Papua New Guinea - Mafulu (1200 m), Lae-Goroka Road (-8.50°S, 146.00°E), Eastern Highlands Province (paratype);
            Sogeri (-7.56°S, 143.43°E), Central Province.
            Fiji - Labasa, Vanua Levu (-16.33°S, 179.50°E) and Nadi, Viti Levu (-17.67°S, 177.50°E).
            Melanesia - Caroline Islands and Marshall Islands (Tokunaga 1964 as C. javanus)
            Other regions:
            Japan - Shizuoka, Shizuoka Prefecture, Honshu (34.989°N; 138.38°E).
            Malaysia - Minden (5.13°N; 100.13°E) and Bukit Merah Rice Res. Stn, Permatang Pauh, Penang; Tregganu.
            ¿Thailand - Ban Bangkanark, Chachoengsao Province; San Pa Tong Rice Experimental Station, Amphoe San Pa Tong,
            Chiang Mai Province; Ban Mae Kachiang, Amphoe Wiang Pa Pao, Chiang Rai Province (Hashimoto et al. 1981 as C. javanus)
            Central Africa - Blantyre, Malawi.

The adult male was described from Thailand by Hashimoto et al. (1981) as C. javanus.  The cytological description given here is based on Australian, Papua New Guinea and Japanese specimens.