Species z. Possibly C. decorus group

Adult and Pupa not known.

Fourth instar larva a small to medium melanotus-type (fem. 12.6 mm; male 12.1 mm), ventral tubules of moderate length (abt. 1.1-1.2 mm) and about equal length.  Posterolateral tubules about 280-310 µm.  Anal tubules quite long with a constriction in the middle, dorsal slightly longer (abt 480 cf. 430 µm) and over 4 times longer than wide (4.0-4.4x).
Gular region pale to occasionally dark on posterior third, frontoclypeus pale or slightly darkened.  Clypeal aperture about 63 x 15µm, 4.2 times longer than wide.
Mentum (Fig. c) relatively pale with pointed teeth; c1 tooth long, narrow to wider and tapering, c2 teeth very well developed about 2/3 height of centre tooth (type III, or may appear to be IIA if worn), 4th laterals slightly or not reduced (type I).
Ventromentum (Fig. d) about 173-200 µm wide and 3.04-3.67 times wider than deep; 0.98-1.04 times the width of the mentum; separated by 0.29-0.31 of the mentum width; with 43.6 (38-52 striae; VMR 0.29-0.34.Pecten epipharyngis (Fig. a) with about 12-14 often relatively irregular teeth.  Premandible (Fig. c (arrowhead)) with outer tooth about equal to inner tooth which is about 3.2-3.4 times wider.
Ventromentum (Fig. d) with about 39-41 striae which reach just over half way to anterior margin, VMR about 0.24-3.0.  Plates separated by about 0.29-0.31 of mentum width.
Antenna (Fig. b) with basal segment about 4.2-4.7 times longer than wide and about 3.5-3.9 times longer than A2 (i.e. A2 about 0.27-0.30 the length of A1); AR about 1.90-2.04; relative lengths of segments (micron): 143 : 41 : 11 : 12.5 : 7.5.
Width between antennal bases (137-152 µm) greater than that between the S4 setae (104-129 µm), which are separated by about 0.68-0.74 of the fronto-clypeus width.  S5 setae posterior to the nearby RO.
Mandible (Fig. e) with 3rd inner tooth moderately to well developed and darkened (IIB-IIIC); about 11-17 furrows on outer surface near the base; 10-12 taeniae in the pecten mandibularis; Mdt-Mat 23-28 µm; MTR 0.30-0.37.

Cytology:  4 polytene of chromosomes with the pseudothummi arm combination: AE, BF, CD, G.
Arm G at least partly paired, nucleolus about the centre and generally 2 Balbiani rings in the paired section, one immediately adjacent to the nucleolus, the other subterminal.  No nucleoli in the long chromosomes.  Polymorphic in arms B and D.
Arm A1:    approx. 1 - 2c, 3 - 2d, 15 - 13, 9, 4 - 8, 10 - 19            i.e. Inv8-15 from holomelas.
Arm B:    Puff (group 7) proximal in arm, with distal dark bands.  Complex inversion begins in this group.
Arm C1:    Typical constriction (groups 3 & 4) just distal of middle of the arm.
Arm D1:
Arm D2:    Inversion of about 1/3 of arm, distal of the centre.
Arm E1:    1 -3e, 10b - 3f, 10c - 13                                    i.e. as aprilinus, etc.
Arm F1:    A puff may sometimes be developed about a third from the centromere.
Arm G1:    Nucleous near center, 2BRs

Found: Ontario – Bear Creek, Carlsbad Springs (45.37°N, 75.47°W), Carleton Co.

            Pools in creek.

See also  C. melanescens,  C. sp. 2t,  C. sp. 3l.

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Modified: 31 March 2021
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