Male terminalia of C. sp. 2g.
A typical C. decorus-type hypopygium.
Adult:
Male (based on Mississippi specimen)
Wing length: 4.0 mm. Wing width: 0.96 mm. VR 1.0.
Antennal ratio: 3.01.
Frontal tubercles developed, about 56-58 micron.
Setae: Clypeal - 28; Achrostichal - 29; Prealar - 7; Scutellar: anterior - 23; posterior - 18.
Male terminalia of C. sp. 2g.
A typical C. decorus-type hypopygium.
Legs with darkening of the joints of the anterior tarsus and tibia.
Leg lengths (in microns) and proportions as below:
|
|
Fe |
Ti |
Ta1 |
Ta2 |
Ta3 |
|
PI |
1490 |
1450 |
2050 |
1065 |
800 |
|
PII |
1585 |
1440 |
920 |
510 |
360 |
|
PIII |
1661 |
1694 |
1199 |
653 |
510 |
|
|
Ta4 |
Ta5 |
LR |
F/T |
BR |
|
PI |
680 |
325 |
1.39 |
1.03 |
3.0 |
|
PII |
270 |
190 |
0.64 |
1.10 |
|
|
PIII |
300 |
188 |
0.77 |
1.01 |
|
Abdomen: with saddle spots, about 10 setae on 9th tergite. Setae on superior volsella forked.
Female (based on Mississippi specimen)
Wing length: 4.1 mm. Wing width: 1.3 mm. VR 1.02.
Antenna missing.
Frontal tubercles developed, about 45 micron.
Setae: Clypeal - 51; Achrostichal - 17+; Prealar - 6,7; Scutellar: anterior - 21; posterior - 18.
Leg lengths (in microns) and proportions as below:
|
|
Fe |
Ti |
Ta1 |
Ta2 |
Ta3 |
|
PI |
1390 |
1290 |
- |
- |
- |
|
PII |
1620 |
1490 |
860 |
430 |
340 |
|
PIII |
1730 |
1750 |
1280 |
740 |
580 |
|
|
Ta4 |
Ta5 |
LR |
F/T |
BR |
|
PI |
- |
365 |
- |
1.08 |
1.5 |
|
PII |
235 |
180 |
0.58 |
1.09 |
|
|
PIII |
320 |
210 |
0.73 |
0.99 |
|
Pupa: Female abt 9.5 mm (1); male about 9.75 mm. (1) in length.
Spur with about 4 - 10 closely applied spines; cephalic tubercles simple, with no sign of a secondary tubercle.
Larva a medium sized bathophilus type (lateral projections sometimes developed up to about 0.13 mm long) (length abt. 12.5 - 20 mm, female; 17 - 17.5 mm, male); Ventral tubules may be of fluviatilis-type, with anterior pair usually slightly longer (ant. 1-2 - 1.7 mm; post. 1.05 - 1.5 mm). Anal tubules about 3 times as long as wide. Dark gular region and pale frontoclypeus. Mentum (Fig. a.) with somewhat rounded teeth; c1 tooth tall and relatively broad, c2 teeth moderately well developed (type IV, or type II); 4th lateral teeth slightly reduced, almost to level of 5th laterals (type II), although Hilsenhoff & Narf (1968) suggest the 5th laterals are raised. Ventromentum (Fig. c) with about 33-41 striae. Pectin epipharyngis (Fig. d) with about 14-17 relatively blunt teeth, lateral teeth smaller and narrower. Mandible (Fig. e) of type II and with about 16-22 striae near the base. Basal segment of antenna (Fig. b) about 2.9 - 3.5 times as long as wide; fourth segment almost twice the length of segment 3; AR 2.3 - 2.6.
Cytology: 4 pairs of chromosomes with the thummi arm combination AB, CD, EF, G.
Arm G usually paired only at the end away from the virtually terminal nucleolus;
2 Balbiani rings developed - one near the middle, the other near the other end of the
arm. No nucleoli in the long chromosomes. Polymorphism in arms A, B, C and G - polymorphism may be more common in populations in the northeast.
Arm A1: 1a-e,7c-4c, 3i-f, 17a-h, 12c-10, 2c-1f, 15-16, 3e-a, 14-13, 4a-b, 2k-d, 9-7d, 18-19
Arm A2: Simple inversion
Arm B1: Puff (group 7) near distal end of arm, with dark bands (group 8) proximal.
Arm B2: Complex inversion. Dark bands distal to puff.
Arm C1: 1a-e, 3c-2f, 4a-6b, 12b-14c, 12a-11d, 6gh, 17a-16, 7d-a, 6f-c, 17b-18, 15-14d, 1f-2e, 8-11c, 19-22 (Kiknadze)
Arm C2: Inversion of about half the arm towards distal end.
Arm D1: 1 - 3e, 17 - 18d, 14f - 10d, 14g - 16, 21 - 18e, 10c-a, 7d - 3f, 9 - 7e, 22 - 24 (Kiknadze)
Arm E1: 1 - 3e, 5a-e, 10e-c, 3f - 4, 10b - 6a, 10f - 13
Arm F1: 1a-i, 9 - 2, 13c - 17, 10 - 11d, 13b - 11e, 18 - 23 (Kiknadze)
Click here for the polytene chromosomes
Found: Quebec - Rowyn-Noranda.
Saskatchewan - Lake Waskesiu, Prince Alfred National Park.
California - Lake Davis.
Indiana: - Crooked Lake, Angola; Lake Oneotta, Marinette(?); Shafer Lake.
Massachusetts - Connecticut River, Northfield, Franklin Co. and at Northampton, Hampshire Co.
Minnesota: - Lake Christina, Douglas Co.
Mississippi - Belzoni, Humphreys Co.; Jackson, Hinds Co.
New Mexico - Springer Lake, Colfax Co.; Frio Draw and Weber City cut-off, Curry Co.; Canadian River and Ute Lake, Quay Co.
Texas - Quaker Street Plaza, Lubbock.
Wisconsin - Booth Lake; Friebauer Lake, Bayfield Co.; Lake Oneonta, Marinette Co.; Lake Pepin, Pepin Co.; Pine Lake, Oneida Co.; Booth Lake, Walworth Co.
Found in depths to over 10m in lakes.
This is Species 13 of Wülker; the C. attenuatus of Hilsenhoff & Narf 1968 and C. decorus-group species 2 of Butler et al. (1995), who provide a karyotype photograph.