Species w. C. trabicola Shobanov, Wuelker & Kiknadze, 2002
Chironomus species w - Wülker & Martin, 2000.Adult:
Based on Russian specimens from data of Shobanov et al. (2002).
Male - Dark species, thorax almost black, abdomen brown to dark brown, tergites uniformly colored. Sternite I with about 11-36 setae, sternite II with 2-6 lateral and about 70 medial setae. Ratio of 3rd-5th maxillary palpomeres (µm) 416 : 386 : 411; P5/P4 1.06, P5/P3 0.89. AR 5.8-7.3.
Anterior basitarsus with beard, BR ave 5.87. Anterior LR 1.03-1.08; Sensilla chaetica on LII, 22-29.
Legs unusual in that anterior femur is shorter than the anterior tibia.
Leg proportions (micron):
| Fe
| Ti
| Ta1
| Ta2
| Ta3
| Ta4
| Ta5
| LR
| F/T
| BR
| PI
| 1613
| 1818
| 1896
| 1221
| 685
| 449
| 291
| 1.03-1.08
| 0.88-0.93
| 5.25-6.78
| PII
| 1982
| 1846
| 1115
| 735
| 513
| 319
| 233
| 0.59-0.61
| 1.05-1.07
|
| PIII
| 2287
| 2448
| 1632
| 1052
| 780
| 411
| 266
| 0.66-0.71
| 0.93-0.98
|
| Tergite IX with about 12 setae in individual pale areas in center of tergite. Superior volsella closest to E(i)-type of Strenzke (1959), with thickening on the inner side. Inferior volsellae conical, apparently with simple setae, reaching about halfway along the gonostylus, which is broad, usually uniformly colored but sometimes with an obvious light area on external side; narrows sharply over posterior third. Anal point brown narrowing from base to top.
Male hypopygium of C. trabicola from Shobanov et al. (2002).Female - not described.Pupa Thorax dark brown, tergites of abdomen with grey spots, congruent with shagreen areas. Laterosternites dark brown. Abdomen length about 9.9-11.6 mm. Wing sheath length about 2.58-3.02 mm.
Caudolateral spur of segment VIII almost black, usually with one spine, but sometimes with up to three, including a second tip. Fourth instar larva a large salinarius-type, length up to 20 mm.
Gular region, frontoclypeal and other dorsal areas of head darkened; in some specimens there may be a pale spot on the posterior half of the frontoclypeus.
Mentum (Fig. c) of only specimen worn; c2 teeth well separated, but illustration in Shobanov et al. (2002) show it to be type III, fourth laterals appear reduced, but in Russian specimens they appear only slightly reduced (Shobanov et al. 2002). Ventromental plates with 47 - 58 striae. Pecten epipharyngis (Fig. b) with 11 - 16 teeth.
Antenna (Fig. a), AR 1.91-2.34; Ring organ almost half way up A1, A1 about 3.2x longer than wide. Mandible (Fig. d) with 3rd inner tooth pale (type IIA), 12-15 furrows on outer surface near the base. Cytology: 4 polytene chromosomes (A, F and G or C, D and E) with the thummi arm combination AB, CD, EF, G.
Arm G partly unpaired and relatively short (about 20 bands), with three Balbiani rings. Nucleolus median in arm D (group 9) and a small nucleolus in arm A in group 15, near the centromere. The Ellesmere specimen has traB1 and traF1, the occurrence of the alternative sequences traB2 and traF2 in North America is unknown.
Wülker (pers. comm.) notes relationship to C. neocorax. traA1: 1a-2c, 10-12, 3i-d,13f-a, 4-9, 2d-3c, 14-19 ie. as holomelas 2
traA2: 1-2c, 10-12, 3ih, 8d-4, 13a-f, 3d-g, 8e-9, 2d-3c, 14-19
traB1: with the typical position of groups 8-9 in the middle of the arm, flanked distally by dark band groups.
traC1: 1-3, 8-11c, 13-15, 4-6b, 12-11d, 6gh, 17a-16, 7-6c, 17b-22 i.e. as heteropilicornis
traD1: 1 - 3g, 11 - 18d, 9 - 10, 4 - 8, 18e-24; nucleolus in region 9.
traE1: 1a-c, 2e - 3e, 5 - 8g, 2d - 1d, 8h - 10b, 4 - 3f, 10c - 13 i.e. as albimaculatus
traF1: 1 - 9f, 11h - 17, 10d-a, 11g-a, 18 -23
traG1: three BRs (proximal, medial and distal), paired through anterior two.Found: British Columbia - Springhouse (51.97; -122.13) (R.A. Cannings)
Nunavut (formerly North West Territories) - Skeleton Lake, Hazen, Ellesmere Island (81.826; -71.483) (Oliver & Corbet, 1966).
Alaska - west shore of Prudhoe Bay, EWD1, tundra pond east of West Doc pad (M.G. Butler).
Russia - Ice Sea coast: Lena Delta (Ust'Lena reserve, Danube Island, pool on polar station area, Type locality), Dikson, Archangelsk.Cytology partially described by Wülker & Martin (2000). Full cytological and morphological description by Shobanov et al. (2002) [ Return to Index| Go to References ] |