Oriental Chironomus: C. incertipenis

Chironomus incertipenis Chaudhuri & Das 1996

New name for Chironomus niger Chaudhuri, Das & Sublette 1992: 21 (Name preoccupied by Wiedemann)
Other names probably incorrectly attributed to C. incertipennis (lacking dark anal point):
Chironomus species 1 Sharma et al. 1990
Chironomus plumosus form A Tripathi et al. 2002
Chironomus plumosus form B Sharma et al. 2004.

All morphology from Chaudhuri, Das & Sublette 1992. Many of the measurements seem unrealistic to be millimetres, as claimed.

Adult

Male
Body length 5.68-6.32 mm; Wing length 2.34 (1.96-2.40) mm; Wing width 0.78 (0.68-0.82) mm., VR 1.01 (1.00-1.03).
Head: Vertex with 18 setae. Frontal tubercles well developed
Clypeus with 28 setae. Relative length of palpomeres: 7 : 6 : 22 : 25 : 31.
Thorax yellow with 3 dark brown vittae. Setae: Acrostichal - 17 biserial; dorsocentral - 24 biserial; prealar - 4; supraalar - 1; Scutellar - 26-28.
Legs with femora, tibia and tarsomeres 1-3 yellow, but tarsomeres with dark apex and tarsomeres 4 and 5 brown. Leg proportions and ratios (units not stated):

	Fe	Ti	Ta1	Ta2	Ta3	Ta4	Ta5	LR	F/T	Ta5/Ti
PI	55	47	79	42	38	32	16	1.67	1.17	0.34
PII	56	51	32	19	14	8	6	0.63	1.10	0.12
PIII	64	62	49	27	21	12	8	0.79	1.03	0.13

Abdomen yellowish, tergites II-V with brown oval median spot. About 8-14 setae on tergite IX. SV appears to be a D-type, but may have a beak like some members of the C. samoensis group. Anal point dark brown and widest at base - a diagnostic characteristic.

Adult characters of C. incertipenis from Chaudhuri et al. (1992) (as C. niger)

Female
Body length 5.75 (5.61-5.98) mm; Wing length 2.79 (2.89-2.87) mm, width 0.99 (0.96-1.06) mm.
Antennal segments in the ratio 8 : 5 : 5 : 6 : 11; AR - 0.46; A5/A1 - 1.38
Genocoxapodeme VIII ovoid, Goxosternapodeme well developed and bow shaped. Gonapophysis VIII divided into an elongated dorsomesal lobe and a stout ventrolateral lobe, apodeme lobe prominent. Postgenital plate broad. TX a narrow crescent; Cerci stout and finely setose, margins curved and possibly a basal bulge on ventral margin.

Pupa:Exuviae grey.  Length 6.22-6.62 mm (fem.); 6.98-8.04 mm (male).  Frontal tubercles 0.06-0.08 mm long and 0.080-0.087 in diameter at base.
Wing sheath 1.58-1.72 mm long.  Respiratory organ with an elliptical base, 0.11 mm wide.
Abdomen with usual Pedes spurii B caudolaterally on segment II and Pedes spurii A on segments IV-VI.  Tergite I bare, tergites II-Vi with median shagreen, tergite VII with two longitudinal patches and tergite VIII with a V-shaped patch of shagreen.
About 28-40 recurved hooks posteriorly on tergite II
Caudolateral spur of segment VIII with about 4 spines

Pupal characters of C. incertipenis from Chaudhuri et al. (1992) (as C. niger)

Fourth instar larva: A plumosus-type larva, 6.25-12.64 mm long. Gula and frontoclypeus apparently not darkened. Ventral tubules illustrated as about the same length, anal tubules as long and narrow, about 3.5 times longer than wide.
Mentum (Fig.10g) with 4th lateral hardly reduced (type I), centre trifid tooth with c2 teeth well separated (either type IIa or III).
Pecten epipharyngis (Fig. 10d) with about 13 sharp teeth. Ventromentum (Fig.10h) about 0.042-0.05 wide, striae finishing before the margin.
Antenna (Fig.10b) with A1 about 3 times longer than wide, Ring organ about 0.3 up from the base; AR 1.74-1.79; A2/A1 about 0.27; relative lengths of segments - 22.3 : 6.1 : 1.9 : 3.1 : 1.6.
Premandible (Fig.10e) with 2 unequal teeth, outer long and pointed, inner blunt
Mandible (Fig.10f) about 0.19-0.23 mm long; third inner tooth apparently separated and darkend (type IIIC), pecten manibularis shown with 10 setae.

Cytology: De and Gupta (1994) described polytene chromosomes that they attributed to this species (as C. niger). However, as with most subsequent work claimed to be this species, they actually described C. species PK2.

Found: Type locality - Barasat, West Bengal, INDIA.
Other Indian localities: Varanasi - Banaras Hindu University.
Singapore, and Japan, but all other than type locality are probably misidentifications.

All life stages described by Chaudhuri et al. (1992) as C. niger. This species is apparently smaller than C. flaviplumus B, which is often incorrectly called C. incertipenis.
The original Chaudhuri et al. (1992) name related to the dark anal point.

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