Description of holotype of Chironomus timmsi (in prep)
Holotype adult male:
Reared male 3, collected Lake Edward, South Australia on 30.viii.1973.
Wing length 4.26 mm; wing width 0.91 mm; VR 0.96; about 32 setae on squamal fringe; 5 SCf on brachiolum.
Head: Face dark green, base of antenna black, antennae blackish brown. AR 3.48; cephalic tubercles 19 µm long; clypeus about 0.78 of the diameter of the antennal pedicel; 46 clypeal setae.
Palpal proportions (micron): 59 : 70 : 240 : 240 : 343.
Thorax greenish black, with black stripes, postnotum and sternopleuron.
Thoracic setae: Acrostichal abt 16; Dorsolaterals - 19 in multiple rows, beginning at suture; Prealars - 8; Supra-alars - 2; Scutellars with a row of 16 large setae at posterior and scattered rows of 23 smaller setae anterior to them.
Legs brown, darkened at knees, last tarsal segments black. Anterior basitarsus with a sparse beard,
Leg length and proportions (micron)
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Fe
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Ti
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Ta1
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Ta2
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Ta3
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Ta4
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Ta5
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LR
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F/T
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BR
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PI
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1450
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1370
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1860
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1035
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790
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840
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385
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1.36
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1.06
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4.5
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PII
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1575
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1525
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930
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550
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420
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270
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1955
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0.63
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1.05
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PIII
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1845
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1915
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1335
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805
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785
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395
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230
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0.70
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0.97
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Male terminalia distinctive due to essentially spatula-like SVo, unlike any of the Strenzke types, perhaps closest to his S-type, as well a large extension of the base, covered in fine setae comes up lateral to it. IVo with simple setae. Gonostylus moderately swollen to about middle then narrowing gently over posterior third. 14 setae in a single patch on tergite IX, 5 or 7 large setae and one small seta at tip of gonostylus.
Pupal exuvia: Exuvia relatively pale, brownish; length about 10.3 mm, length of inner margin of wing case 2.2 mm.
Cephalic tubercles 63 µm, about twice as long as wide, subterminal seta about 55-60 µm. Respiratory base about 149 µm long, with the tracheal patch markedly narrowing in the centre; HR about 2.8. Anterior to the base there is a patch containing 2 or 3 loops and 2-3 setae.
Hook row on posterior margin of tergite II with abt. 90 hooks occupying about 55% of the segment width. Pedes spurii B well developed laterally on segment II, smaller on segment III; pedes spurii A well developed on segment IV (length 240 µm; and about 0.24 of segment length), but small and distinct on V and VI. L-setae present at the junction of segments III/IV and IV/V, arising from the posterior margin of the anterior segment, the setae are difficult to measure but seem to be about 100 µm long, possibly longer at the IV/V junction.
Caudolateral spur of tergite VIII generally with one spine but occasionally with two spines.
About 107 taeniae on each side of the swim fin.
Larval exuvia: Gula and frontoclypeus pale. Clypeal aperture 71 µm long and 3.1 times longer than wide. Ventral head length (VHL) 336 µm, mentum width (MW) 210 µm (0.63 of VHL), length of ventromentum 214 µm, 3.25 times longer than deep and 1.03 times longer than the MW, separated by 31% of the MW and with 37 striae; VMR 0.31.
Mentum with centre tooth quite broad, c1 tooth 25 µm wide, c2 teeth well developed and separated; 4th laterals reduced almost to the level of the 5th laterals (type II).
Pecten epipharyngis with 13 teeth. Premandible with outer tooth shorter (possibly due to wear) but relative width of the teeth cold not be determined.
Distance between the antennal bases (157 µm) greater than that between the S4 setae (144 µm), which are separated by 75% of the width of the frontoclypeus at that point.
Antenna relatively short - A1 0.43 of VHL, and 3.60 times longer than wide, RO about 0.46 up from base of segment; AR 2.15, segment proportions (micron) 131 : 36 : 9 : 12 : 7.
Mandible probably type IIB; 14 furrows on outer surface at the base; 12 taeniae in Pma; Mandible Tooth Ratio 0.35.
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