Male terminalia of C. species b.
Note relatively short gonostylus, and the superior volsella similar to that of C. blaylocki.
Adult: The adult male is a typical member of the C. decorus-group. The gonostylus is relatively short and stout compared to those of C. bifurcatus or C. blaylocki. The superior volsella shows similarities to that of C. blaylocki.
Male terminalia of C. species b.
Note relatively short gonostylus, and the superior volsella similar to that of C. blaylocki.
Pupa: Pupal spur (below) with about 5 spines along the outer margin.
Larva of the plumosus-type with long ventral tubules, posterior pair normally longer (anterior 1.6 - 2.3 mm; posterior 2.0 - 2.8 mm). Length, female 17.2 - 14.4 mm; male 15.3 - 12.0 mm. Gular region darkened, frontoclypeus normally darkened, occasionally pale. Mentum with rounded teeth, c2 teeth of centre trifid tooth well seperated (type II). Antenna with basal segment about 3.6 times as long as wide; AR about 2. Anal tubules relatively long, with a median constriction, about 700 micron in length.
Cytology
: 4 pairs of chromosomes with thummi arm combination AB, CD, EF, G.
Arm G normally paired with subterminal nucleolus and Balbiani ring about one third
from other end. No other nucleoli. Polymorphic in arms A, B, E & F.
Arm A1: 1a-e, 4d-a, 13-15, 3e-2d, 9-8, 5-7, 16d-a 1f-2c, 10-12, 3i-f, 17-19 (Wülker)
Arm B1: Puff with proximal dark bands (groups 7 and 8) near distal end of arm.
Arm B2: Puff with distal dark bands (groups 8 and 7) about 1/3 from end of arm, possibly as B of 'blaylocki'
Arm C: possibly as C of sp. a and C2 of 'blaylocki'
Arm E1: 1 - 3e, 5 - 10b, 4 - 3f, 10c - 13 ie. as maturus, stigmaterus, 'blaylocki'
Arm E2: approx. 1 - 3e, 6 - 8, 5, 9 - 10b, 4 - 3f, 10c - 13
Arm F1: 1, 9 - 2, 10 - 23 ie. as 'blaylocki'F1
Arm F2: 1, 9 - 2,10a-d, 17 - 11, 18 - 23 (Wülker)
Click here to see the polytene chromosomes
Found: Ontario - Dunrobin, Carleton Co.; Bear Creek, Carlsbad Springs, Russel Co.
Wisconsin - Arboretum, Madison, Dane Co.
Shallow pools, including in creeks.
This species is very close to C. 'blaylocki', possibly a subspecies. Some information on larval morphology and a photograph of the chromosome complement are given in Wülker et al. (2009)