North American Chironomus: C. sp. 3d (nr. annularius)

Species 3d. C. nr. annularius sensu Strenzke (1959)

Species 9 - Martin (1979) and Wülker, Devai & Devai (1989).

Currently European specimens called C. annularius are listed in 3 other BOLD bins: BOLD:AAU4046; BOLD:AAU4047 and BOLD:AAW3973

I am grateful to Prof. P. Michailova for pointing out that this North American species is identical to material of C. annularius from Russia.

Adult

Male (Based on description of Strenzke, 1959):
AR 4.0 (abt 3.72-4.28)
Wing length 3.9 (abt 3.6-4.2) mm, width about 1.3 mm.
Thorax greyish yellow, bands black or red-brown with more or less darker flecking. Setae - acrostichal abt 18-27; dorsolateral abt. 27-36; prealar about5-8; supra alar abt 1-2; scutellar abt 33-48.
Legs with tarsi darkened. LR1 abt 1.35-1.45; F1/Ti1 abt 1.04-1.08.
Adbomen with most of seg I yellow brown, segs II-V darker, II-IV with anal border extended medially.
Hypopygium with abt 4 setae in patch in centre of TIX; Superior volsella of E-type (variable); Inferior volsella markedly narrowed at the tip, gonostylus narrowing gently over posterior half.

Adult female of C. species 3d.From BOLD database: specimen A08z+1337961340

Female (from specimens in BOLD):
Wing length 4.5 (abt 3.5-5.0) mm, VR 1.04
General colouring dark brown; palps brownish black; thorax yellow with bands brown, postnotum dark; abdomen dark brown, with lighter posterior margin on segments 2-4;Legs yellowish with darkening at knees and tarsal segments darkening to blackfrom Ta1.
Antennae brown, darkening towards the tip; AR about 0.36-0.44; A5/A1 about 1.13-1.17; approximate segment lengths (micron) 210 : 140 : 130 : 140 : 242.
Approx. lengths of palpal segments 2-5 (micron) 50 : 225 : 275 : 420.
Legs: Approximate lengths and proportions (micron):

	Fe	Ti	Ta1	Ta2	Ta3
PI	1525	2925	2275	1080	710
PII	1590	1275	1000	500	280
PIII	1765	1760	1065	690	485
	Ta4	Ta5	LR	F/T	Ta4/Ti
PI	565	225	1.53	0.93-1.15	0.38
PII	250	195	0.90	1.40	0.25
PIII	300	205	0.52-0.69	0.92-0.94	0.15-0.18

Pupa: some pupal characters known from a late prepupa.
Caudolateral spur on segment VIII (below) with about 3-5 spines.

Anal fringe with about 94 setae in multiple rows.

Fourth instar larva a medium length plumosus-melanotus-type; length 15.3-17.8 mm, very similar to that of sp. 3b but gular region darker (posterior 2/3 dark to very dark, extending beyond width of mentum and generally higher at edges), frontoclypeus normally pale, but occasionally very slightly darkened or with a streak along the middle and on edges. Ventral tubules relatively long, about equal in length or anterior pair longer (ant. 0.92-1.80, 1.42 mm; 0.92-1.80, 1.34 mm); lateral tubules variable (about 160-240 µm). Anal tubules relatively short (420-640 µm) with no constriction, about 2-3.2 times longer than wide, ventral pair usually shorter.

Anal tubule of C. species 3d.
Mentum (Figs. e & f) with 4th laterals only slightly reduced (type I-ii), central trifid tooth somewhere between type IB and III, with c2 teeth separated to about 1/3 depth of c1 tooth, which can also look like type IIA if worn.
Ventromental plates (Fig. g) about 237-270 µm long, 3.5-4 times wider than deep, 0.99-1.07 times the mentum width; IPD about 40% of width of mentum, with about 42-43 striae; VMR 0.27-0.30.
Premandible (Fig. b) closest to type D with with relatively broad inner tooth about 3.5-4 times wider than the outer;teeth relatively short, only about twice as long as the greatest width. Pecten epipharyngis (Fig. a) with about 16-17 pointed teeth.
Antenna (Fig. c) with basal segment about 0.35-0.4 of VHL, about 3.5-3.6 times longer than wide, RO just under half way up the segmant; AR about 2.2-2.4, relative length of segments (µm) 152 : 35 : 9 : 15 : 8.
Distance between the antennal bases less than that between the S4 setae, which are separated by about 78-81% of the FC width.
Mandible (Fig. d) with 3rd inner tooth relatively well separated, but still relatively pale (type II-IIIB), 16-19 grooves on outer surface at base; 11-16 taeniae in Pecten mandibularis; MTR 0.21-0.34.

Cytology: 4 polytene chromosomes with the thummi arm combination AB, CD, EF, G.
Arm G with a median and terminal Balbiani ring, with a nucleolus and heterochromatin at the other end, separated from the BRs by a distinct constriction. Nucleoli developed subterminal in E (may be a double structure), proximally to the olive in arm A and also proximal in C. Polymorphism in arms A?, C, E and G.

h'annA2: 1 - 2c, 10 - 12a, 13ba, 4a-c, 2g-d, 9 - 4d, 2h - 3, 12cb, 13 c- 19 as h'antA1, h'pluA2.
h'annB2: Puff, with distal dark bands (gps 8-7), just distal to typical bands 24-27
n'annC3: 1a - 6b, 11c - 8a, 6c - 7d, 16 - 17a, 6hg, 11d - 15, 17b - 22
n'annC4?: Simple inversion of about 1/3 of arm near the distal end. but could be p'annC1?
n'annD3: 1 - 3g. 11 - 13a, 10a, 7a - 4, 10e-b 13b - 16, 8b - 9, 7b-g, 18a-d, 8a, 17a-f, 18e - 24
h'annE1: 1 - 3e, 5a-e, 4hg, 10b - 6, 4f - 3f, 10c - 13 i.e. probably derived from h'annE2
h'annE2: 1 - 3e, 5a - 10b, 4h - 3f, 10c - 13
n'annF3: 1 - 4b, 8c - 4c, 17 - 13, 10a-d, 18c-a, 11 - 12, 9f - 8d, 18de, 19 - 23
n'annG3: subterminal nucleolus and median and terminal BR this could be a subterminal inversion of p'annG1 (not p'annG2)

Found: Alberta - Amisk Lake; Astotin Lake, Elk Island N.P. (53.685°N, 112.86°W), Two Hills (53.7104°N, 111.744°W) (both BOLD)
British Columbia - New Afton Mine, Kamloops (50.663°N, 120.504°W) (BOLD).
Manitoba - Riding Mountain N.P. (50.676°N, 99.898°W) (BOLD).
New Brunswick - Rothesay Park(45.338°N, 65.996°W) (BOLD).
Ontario - Prairie Smoke, Carden Alvar (44.645°N, 79.095°W (BOLD)
Prince Edward Island - Miscouche (46.432°N, 63.864°W)(BOLD).
Saskatchewan - Crooked Lake (50.60°N, 102.75°W), Pasqua Lake (50.78°N, 104.00°W), & Round Lake (50.53°N, 102.37°W),
Qu'Appelle River; Mission Lake, 2 Km w. Lebret (50.75°N, 103.70°W); Big Quill Lake abt 1 ml s. Dafoe (51.55°N, 104.72°W).
Yukon Territory - Lake Laberge (60.958°N, 135.184°W) (BOLD).
Indiana - Crooked Lake, Angola.
North Dakota - Larimore Dam, Grand Forks, Co.; Warsing Dam, Eddy Co.
Wisconsin - Booth Lake (Hilsenhoff & Narf 1968), East Horsehead Lake, Oneida Co.; Grandportage Lake, Iron Co. (Hilsenhoff & Narf
1968); Kegonsa Lake, Dane Co. (Hilsenhoff & Narf 1968); Pine Lake, Pleasant Lake, Walworth Co.

Lakes and dams

Larva very similar to that of sp. 3b but gular region darker, frontoclypeus pale, and lateral projections shorter. Some information on arm F published by Martin (1979), and Wülker, Devai & Devai (1989), under the name Species 9. Some larval characters given in Hilsenhoff & Narf (1968) as Chironomus n.sp. D. Karyotype described by Kiknadze et al. (2012) and (2016).
It is possible the specimen sequenced in Guryev et al. (2001) may have been a misidentified C. muratensis as it is closest to that species in GenBank acessions.

| Return to Index ]