North American Chironomus: C. harpi

Species 2z. C. harpi Sublette, 1991

This species is in BOLD Bin: BOLD:AAJ4275
The nearest neighbor in BOLD is BOLD:AAG5472 an unidentified species mainly from central and western North America

Adult:

Described by J.E. Sublette in Wülker, Sublette & Martin (1991).

Male: Ground color of head and thorax yellowish, antennal pedicels, thoracic vittae, postnotum, sternoplueron, postnotum and abdomen blackish brown, but abdominal color seasonally variable with late spring specimens with only a basal dark band and distal yellowish band increasing from 1/3 on TII to 2/3 on TV. Legs also seasonally variable from all dark to F,Ti and Ta1 pale on all legs.
Wing length 3.20 (2.63-3.67) mm.; VR 0.99; r-m crossvein darkened; 26 (23-41) setae in squamal fringe.
Head: AR 3.88 (3.69-4.32); frontal tubercle 15-31 µm; clypeus 0.75 width of ant. pedicel, with 32 (28-40) setae; palpal proportions (segs 2-5) 55 : 195 : 234 : 234.
Thorax with small but distinct mesonotal tubercle. Setae: Acrostichal - 19 (16-20); Dorsolateral - 25 (21-30); Prealar - 5 (4-6); Supraalar - 1; and Scutellar - 29 (23-39).
Leg ratios: PI 1.39 (1.33-1.43); PII 0.59 (0.57-0.62); PIII 0.72 (0.71-0.73); BR 3.36 (2.2-4.67).
Setae on TIX 4 (2-9); Superior volsella long, narrow and blunt tipped, closest to E(g)-type of Strenzke (1959); Inferior volsella reaching to about end of anal point and about 2/3 along the gonostylus, which is quite swollen and narrows sharply about posterior third.

Male hypopygium (from Wülker et al. 1991).

Female: Coloration as in males but coloration darker, legs blackish.
Wings: length 3.17-4.17; width 1.02 mm, VR 0.94-0.95; anterior wing veins darkened. 3 Scf on brachiolum, 28-43 setae in squamal fringe.Head: Frontal tubercles conical, 23-31 µm long; antennal proportions (micron) (fraction of neck in brackets) : 193 (0.29) : 125 (0.31) : 115 (0.33) : 110 (0.28) : 252 ; AR 0.46; A5/A1 1.36. Palpal proportions (micron): 65 : 70 : 211 : 257 : 351; P5/P4 = 1.37. Clypeus width abt 1.7 times the diameter of the antennal pedicel with about 39 setae.
Thoracic setae: Acrostichal - about 21; humeral - 11; dorsolateral - 25-27; prealar - 5-7; supraalar 1-2; scutellar - about 16 large in posterior row and 18 smaller in 2 anterior rows (total 24-34).
Legs lengths (micron) and proportions:

	Fe	Ti	Ta1	Ta2	Ta3	Ta4	Ta5	LR	F/T	Ta4/Ti
PI	1390	1290	1975	935	720	720	345	1.45-1.53	1.06-1.07	1.9-2.0
PII	1495	1430	785	430	310	205	175	0.54-0.55	1.04
PIII	1605	1645	1125	665	515	300	195	0.68-0.70	0.98

BR 1.79; Sensilla chaetica on Ta1: PII 67; PIII 68.

Genitalia of the allotype female, illustrated in Wülker et al. (1991), shows only the labium and ventrolateral lobe. From other females, segment X wider than usual for a greater part of the length (see figure below), dorsal end hard to see, about 4.75 times longer than its greatest width with 11-18 setae; the cercus has the dorsal margin slightly shorter than the ventral margin which has a basal bulge, so that the dorsal margin is longer than that somewhat rounded ventral margin.

Female cercus (right) with segment X (left).

See Pupa, Fourth instar larva and Cytology

Found: Ontario - Point Pelee National Park (41.959°N, 82.518°W) (NCBI)
Arkansas - 40 km sw. Little Rock, Saline Co. (Type locality) (plumosus-type); White River National Wildlife Refuge, Arkansas
(Chordas et al. 2004.)
Illinois - Bradley's Acid Pit (37.90°N, 89.53°W), Jackson Co. (thummi-type)
New York - 2-2.5 km e. Middleport (43.22°N, 78.47°W), Orleans Co. (plumosus-type)
South Dakota - 3.5 km w., 5 km s. Lake Andes, Charles Mix Co.

Pools with low pH.

Morphology of all life stages, and cytology described by Wülker, Sublette & Martin (1991). Some ecological data given by Harp and Campbell (1973), as C. plumosus; Harp and Hubbard (1972), as C. n.sp. and Bates and Stahl (1985), as C. nr. maturus. The South Dakota population may represent a distinct species, however more samples are required to clarify this. In the mean time it is assumed that this is just geographic differentiation.

Molecular Data
The Barcode sequence of the mitochondrial COI gene, for 2 larvae (including one collected along with the paratypes from Bradley's Acid Pit), are available on the BOLD database (CotW024-08 and 067-20). Further sequences from Pt. Pelee National Park, Ont., Canada are available in NCBI (incl. KJ165251).

See also C. bifurcatus, C. sp. b, C. sp. c, C. sp. j, C. sp. 2a, C. "proulxi", C. "butleri", C. decorus Joh., C. sp. 3h, C. sp. 3i, C. sp. 3j, C. sp. 3r, C. blaylocki, C. mozleyi, C. winnelli.

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