12. Chironomus n.sp. NZ12

The adult of this species is not known for certain.    However, a male with associated pupal exuvia, which is not C. analis the other species known from Lake Ngapouri, has the following characters:
Wing length: 4.06 mm, width 0.88 mm; VR 1.02.
AR about 3.35.
Small frontal tubercles, about 13 micron; about 29 clypeal setae.
Anterior tibiae and tarsus bearded, BR about 3.7.
Abdominal tergites with brown bands covering the anterior 2/3 of segments 2 to 6 and about 4/5 of segments 7 and 8.    4 setae on 9th tergite.    Superior volsella hooked.

Pupae:    Exuvial length about 8.8 - 9.7 mm; length of inner margin of wing case about 1.8 mm; Cephalic tubercles abt 50 micron.    About 95 recurved hooks and about 85 setae in the hair fringe on each side.    Muscle scars on tergites faint.    Pupal spurs with 5 - 7 spines.

Larval Morphology: bathophilus-type larva.   Length about 17.2 - 18 mm (female) and 13.8 - 14.2 (male). Anterior ventral tubules about 0.86 - 1.6 mm; posterior about 0.82 - 1.46 mm.    Head capsule with pale or slightly darkened frontoclypeus, pale or slightly dark posterior third of gula.

Cytology:    4 polytene chromosomes with the pseudothummi arm combination (AE, BF, CD, G).    Arm G without a nucleolus, but with an obvious subterminal BR.     Polymorphism in arm B, with B2 apparently the more common sequence.

Arm A1:    1a-e, 11 - 10, 2c - 1f, 3e - 2e, 7 - 4, 12a-c, 3i-f, 9 - 8, 2d, 13 - 19                                                        as nzlA2
Arm B1:    Puff (group 7) with reduced dark bands nearer distal end of arm.                                              as nzl B2
Arm B2:    Distal inversion including the puff (group 7) that returns it to near the middle of the arm.        as nzlB3
Arm C1:    as nzlC3
Arm D1:    1 - 2, 16 - 15, 10ed, 3a-d, 9 - 4, 11 - 12, 3g-e, 13 - 14, 10a-c, 17 - 24                                                 as nzlD2
Arm E1:    1a-c, 5 - 7c, 10g-c, 3f - 4, 1d - 3e, 10b - 7d, 11 - 13                                                                             as nzlE3
Arm F1:    1a-e, 12 - 15c, 2c - 10, 2a, 11i-a, 2b, 15d - 23                                                                                      as nzlF2
Arm G1:    No nucleolus, but an obvious subterminal BR.                                                                               as nzlG2?

Click here to see the polytene chromosomes

Localities:
North Island:
    Lake Ngapouri, Waiotapu, South Auckland (NZ.9) (D.J. Forsyth, Jon Martin & S. Ibarraran) 1970-1973, 29-viii-2007.
    Lake Rotoiti, about 16 Km north east of Rotorua, South Auckland (NZ.19) (Jon Martin, D.J. Forsyth & S. Ibarraran) 7-xii-1973 & 29-viii-2007.

Initially included with C. novae-zelandiae, but shows consistent differences in the lighter larval head colour and some unique banding patterns.    The existence of this species was first indicated by the barcoding analyses of Sofia Ibarraran.

See also C. 'spilleri',  and C. species NZ11.

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Modified: 26 June 2009
Access: Unrestricted
Copyright © 2008-2009, Jon Martin.