2. Chironomus zealandicus Hudson, 1892

Redescribed by Hutton 1902.

        C. species a. (Forsyth, 1978).

In BOLD Bin: AAS1265.

Hutton's description, aside from a detailed colour description, provides the information that length is 6-8 mm, wing length about 5.5 mm, and LR about 1.3.

Additional specimens:

Males
AR about 3.6-4.0.
Wing length 4.6-5.5 mm; width 0.96-1.16 mm.; VR 0.95-0.96.
Cephalic tubercles present 10-35 micron.
Setae: 16-33 Clypeal; 16-20 Dorsocentrals; abt 6 Prealars; 17-29 Scutellar, sometimes in two rows (posterior row larger) sometimes in multiple rows (anterior rows more numerous than posterior row).

LR 1.3-1.44; Anterior tarsi with a short dense beard (BR about 3-6) and sparse longer hairs (BR about 6-9).
Leg lengths (microns) and proportions:

 
Fe
Ti
Ta1
Ta2
Ta3
PI
1600
1540
1980
1230
870
PII
1710
1720
960
650
480
PIII
2110
2200
1430
940
700
 
Ta4
Ta5
LR
F/T
BR
PI
700
350
1.29-1.44
1.03-1.08
6-9
PII
320
230
0.55-0.59
0.96-1.08
 
PIII
460
270
0.65-0.70
0.94-1.00
 

Abdominal tergites with a broad dark band covering most of the surface, leaving only a narrow pale band at the posterior edge.
Anal point relatively narrow, superior volsella of E-type (between h and i).
About 8 - 15 setae at base of anal point.

Females
Wing length abt 4.4 mm, width abt 1.2 mm, VR abt 1.06, LR abt 1.36.
Head: Cephalic tubercles about 33 micron; antennal segments (micron) 211 : 136 : 141 : 146 : 221 ; AR abt 0.35; A5/A1 abt 1.05.  Palpal proportions (P2-P5) 80 : 231 : 291 : 432.
Setae: abt 41 clypeal; unclear Acrostichals; abt 19 Dorsocentrals; abt 6 Prealar; ant row abt 18, post row abt 15 for Scutellars.
Leg lengths (microns) and proportions:


Fe
Ti
Ta1
Ta2
Ta3
PI
1633
1443
1962
1443
785
 
PII
1646
1750
886
494
367
 
PIII
1873
1873
1228
734
570
 
Ta4
Ta5
LR
F/T
Ta4/Ti
 
PI
608
316
1.36
1.13
0.31
 
PII
253
190
0.51
1.05
0.12
 
PIII
468
228
0.66
1.00
0.12
 

Pupa: Length about 10.2-12.5 mm (males), inner margin of wing case about 2.45 mm (males).
Cephalic tubercle about 134-160 micron, with sub-apical seta about 78-88 micron.
Muscle scars on abdominal tergites slightly darkened; about 65-100 recurved hooks on abdominal segment II.
Posterolateral spurs of segment VIII with numerous spines (18-22) spreading out like a hand with the fingers spread.
About 110-115 multiple ranked setae on each side of the anal lobe.

Larval Morphology: a salinarius-type larva.  Largest NZ species, length about 15.3-21.5 mm (female), 15.3-18.7 mm (male).  Anal tubules short and often tending to a point.
Head capsule with frontoclypeus and most of the gular region very dark.
Most distinctive feature is the high number of striae (75-99) on the Ventromental plate.
Mentum of type II (i.e 4th laterals reduced at least to the level of 5th laterals) with central trifid tooth of Type II, although sometimes the c2 teeth are less separated from the c1 tooth.
Pecten epipharyngis with about 12-15 relatively sharp teeth, some reduced.  Premandible with the two blades about equal in length, inner blade about twice the width of the outer (2.0-2.5).
Antennal segments in proportions (micron) 163 : 37 : 8 : 15 : 8 ; AR 2.0-2.3; basal segment of antenna relatively long and narrow, about 3.1-3.7 times as long as wide.
Mandible with 3rd inner tooth darkened and often fully separate (i.e. Type IIIC); about 17-23 striae on the outer surface near the base.

Cytology: 3 polytene chromosomes, modified pseudothummi-complex arm combination (BF,CD,GEA).
Three nucleoli, one in arm G, one proximal and another medial in arm F(Lentzios & Stocker, 1979).  The medial nucleolus may not always be developed, since Lentzios & Stocker (1979) did not find it in their material.
zeaA1 differing from oppositus A4 sequence by a simple inversion 11-2e; arm E pattern not typical but zeaE1 appears to differ by a small inversion 5c-7 from oppositus E1.  Arm F differs from that of novae-zelandiae, etc., by inversion of the region 7 to 11.
Considerable polymorphism in arms A, B,C, E, and G(?); sex determiner in arm C, probably near the centromere (Martin & Lee, 1984).
Lentzios et a. (1980) give some information on the number and location of C-bands.
zeaA1:    1a-e, 2g - 3, 1f - 2e, 10 - 11, 2f-d, 8 - 9, 3f-i, 12c-a, 4 - 7, 13 - 19
hypoth:    1a-e, 2g - 3, 4a, 12a-c, 3i-f, 9 - 8, 2d-f, 11 - 10, 2e - 1f, 3e-b, 4b - 7, 13 - 19
zeaA2:    1a-c, 10 - 11, 2f-d, 8 - 9, 3f-i, 12c-a, 4a, 3a - 2g, 1ed, 2e - 1f, 3e-b, 4b - 7, 13 - 19
zeaB1:    Puff, with proximal dark bands (groups 7 and 8), in proximal third of arm.
zeaB2:    Inversion of distal end of arm, distal to large puff.
zeaC1:
zeaC2:    Inversion of about 2/3 of arm.
zeaD1:    1-2, 16-13, 18, 5-3e, 10a-c, 6-9, 3d-a, 10d-12, 19-24
zeaE1: (approx)  1?- 3e, 10b - 8, 5c - 7, 5b - 3f, 10c - 13
zeaE2: (approx)  1?-f, 4b - 5b, 7 - 5c, 8 - 10b, 3e - 2, 4a - 3f, 10c - 13
zeaE3: (approx)  1?- 3e, 10b - 8, 5c - 7, 5b - 3f, 10c-g, 12 -11, 13
zeaF1:    1 - 2a, 10 - 8, 11 - 15c, 2c - 7, 2b, 15d - 23                (In7 - 11 from oppositus F3)
zeaG1:    fused to arm E.
zeaG2:    possible inversion

Molecular:
MtCOI - GenBank (AF192209.1) and sequences in BOLD Bin: BOLD AAS1265 (see above)
gb2Β - GenBank (AJ003813)
gb9 - GenBank (AJ003814.1)

Known Localities

This appears to have been the "salinarius-type" studied by Robb (1966).  It is referred to as C. zealandicus Type 2 by Lentzios & Stocker (1979) and Lentzios et al. (1980), who received their material from Lake Okaro.
Martin (1998) gives some information and drawings of immature stages.

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Modified: 8 September 2020
Access: Unrestricted
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