Species 3l.  Chironomus species 3l

A C. decorus or C. riparius group species.
Adults and pupa unknown.

Fourth instar larva a medium sized plumosus-type (len. female 13.5-15 mm;  Ventral tubulesT well developed, posterior pair longer (ant 1.68-1.72 mm; post 2.08-2.16 mm).  Anal tubules relatively long, with a slight constriction in the middle (372 x 140 µm).  Gular region pale or only slightly darkened,  Frontoclypeus pale.
Mentum (c, below) of type I, with c2 teeth well separated from the c1 tooth (i.e. type III), the whole central grouping possibly being lower than the arc of the other teeth.
Pecten epipharyngis (a, below) with about 15 broad teeth.  Ventromentum (e, below) with about 41-48 striae.
Antenna (b, below) with relatively long and narrow basal segment, about 3.6 times as long as wide; AR about 1.95-2.15; antennal segments 134 : 35 : 10 : 14 : 7 micron.
Mandible (d, below) of type III, with about 15-17 grooves on the outer surface at the base (f, below); MTR about 0.43.

Cytology: 4 polytene chromosomes with the pseudothummi arm combination AE, BF, CD, G.  All chromosomes closely paired.
Arm G with an almost terminal nucleolus, with 2 BRs approximately equally spaced in the other half of the length of the chromosome.  No nucleoli in other chromosomes.  Arm B with bulb and some distal dark bands about 1/3 from end of arm.
Arm A: Olive (gps x-y) not obvious, but probably about a third from the distal end of the arm.
Arm B: Puff (gp 7) about 1/3 from distal end.
Arm E: approx. 1-2e, 9d-10b, 3a-e, 8-3f, 10c-13                i.e. as anonymus
Arm F: typical bands near centromere
Arm G: Subterminal nucleolus (N) and two distal BR.  Distal end often unpaired.