Asian Chironomus: C. sulfurosus

Chironomus sulfurosus Yamamoto 1990

In BOLD Bin: BOLD:ACH4992
This is the same Bin as C. fusciceps, which has 99.83% homology.

(based on Yamamoto 1990)

Adult:

A dark species, similar in coloration to C. acerbiphilus and C. fusciceps.

Male:
Wing length 2.3 2.6 mm, width 0.7-0.8 mm; VR 0.91 (0.90-0.93).
AR about 2.69 (2.54-2.92), LR 1.42 (1.32-1.52).
Head: Frontal tubercles 12.5-32.5 &4181;m long, about 1.2-2 times longer than wide.
Clypeus with 30-39 setae. Mean palpal lengths (micron): 52 : 60 : 180 : 182 : 234.
Thoracic setae: 15-22 dorsocentrals, biserial at anterior end; 4-6 prealars; 1 supraalar; 26-32 scutellars in about 3 rows.
Leg proportions (micron):

	Fe	Ti	Ta1	Ta2	Ta3	Ta4	Ta5	LR	F/T	Ta4/Ta3
PI	1270	1020	1500	750	630	480	270	1.32-1.52	1.25	0.73-0.77
PII	1300	1110	620	350	270	190	150	0.53-0.58	1.17
PIII	1450	1310	880	500	400	250	100	0.66-0.70	1.11

About 2-11 setae at middle of tergite IX. Superior volsella of S-type; Gonostylus narrowing sharply over posterior third.

Female
Coloration almost the same as C. fusciceps female.
Wing length 2.5-2.9 mm, width 0.8-1.0 mm, VR 0.88 (0.84-0.89). Squama with 16-28 setae.
Leg proportions (micron):

	Fe	Ti	Ta1	Ta2	Ta3	Ta4	Ta5	LR	F/T	Ta4/Ti
PI	1360	1020	1550	770	660	520	280	1.49-1.55	1.25	0.51
PII	1370	1190	640	360	280	210	160	0.52-0.56	1.15
PIII	1500	1370	900	500	420	260	190	0.63-0.69	1.09

Ventral lobe of egg-guide more slender than those of C. acerbiphilus and C. fusciceps; and laterosternite smaller than in those species, separated from TIX by a narrow membranous area and with 2-3 setae; post genital plate very slender and nearly linear. Segment X with 9-17 setae.

Fourth instar larva: A small (length 8-12 mm) essentially melanotus-type larva, but sometimes posterior pair of ventral tubules tending to curl up. Posterolateral tubules short and slender. Anal setae of procercus fused into a single stout bristle. Anal tubules relatively stout, ventral pair apparently longer than the dorsal pair.
Head capsule orange-yellow.
Mentum of type I, center tooth of type IIA. Pecten epipharyngis with about 20 uneven teeth.
Premandibles stout, outer tooth longer than the inner, which is about 1.7 times broader than the outer tooth.
Basal segment of antenna about 4 times longer than wide; ring organ about a quarter up from base; AR about 1.9-2.2; relative proportions of segments (units) 42 : 11 : 2 : 4 : 2.
Mandible with 3rd inner tooth apparently well developed and darkened (type IIIC); Pecten mandibularis with 12 setae; no information on basal furrows.

Cytology: no information, but if related to C. acerbiphilus is likely to be pseudothummi cytocomplex.

In highly acidic waters.

Found: Japan - Kurinodake, Onsen, Kagoshima Pref, Kyushu. (Type locality).

DNA sequence: There is one accession from GenBank which could be this species.
Other sequences from GenBank or BOLD appear to be misidentified:
GenBank accession number AB704937 is actually for a species of Kiefferulus
That in the BOLD database (in BOLD Bin: BOLD:ACH4991) appears to be a species of Glyptotendipes, possibly G. tokunagai.

[ See also C. acerbiphilus; and C. fusciceps]

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