Centre tooth of mentum relatively wide with well separated c2 teeth (type II); 4th laterals not visibly reduced (type I).
3rd inner tooth of mandible clearly demarcated (type III).
Cytology: 4 relatively short polytene chromosomes with the thummi arm combination AB, CD, EF, G.
Arm G partly unpaired with a subterminal nucleolus; only about a dozen visible bands. Nucleolus in arm B and possibly a smaller one in arm F.
Polymorphic in arm B.
Arm A1: 1 - 2c, 10 - 12, 3 - 2d, 9 - 4, 13 - 19 i.e. as in holomelas, cucini, tardus, major, etc.
Arm B1: differs from longistylus by a distal inversion.
Arm C1: 1 - 6b, 11c - 8, 15 - 11d, 6gh, 17a - 16, 7d - 6c, 17b - 22 as aberratus, pilicornis, etc.
Arm D1: proximally similar to longistylus
Arm E1: 1 - 3e, 5 - 10b, 4 - 3f, 10 - 13 i.e as in cingulatus and tardus.
Arm F1: 1 - 23 i.e. Standard as in piger.
Found: California - Spring Valley Lake, nr. Hesperia, Apple Valley, San Bernadino Co.
High altitude lake.
Cytology described as 'C. species Apple Valley' by Wülker (1980) some information on Arm F given in Fig. 3 of Martin (1979) and a photo of arm C with an incorrect band sequence given in Devai et al. (1989).
The larva shows similarity to that of C. nr. annularius (Sp. 3d) but the gular region is not as dark, the FC is darker and the lateral projections longer (Wülker, pers. comm.)
The adult associated with this larva is not known.
From the ecological information for the locality given by Egan and Ferrington (2015), it is likely that this is their "Chironomus aberratus".