Chironomus flaviplumus Type B

This type was identified as C. flaviplumus by H. Yamamoto.  BLAST comparisons of available sequences in GenBank or the BOLD Database reveals that the species is widely distributed from India, Japan, Pakistan (as C. incertipenis), Thailand (as Chironomus sp.).

Previously called C. species PK2 or species PK7.

The species is in BOLD Bin: BOLD:AAW3997 sometimes as C. incertipenis.

Adult

Male:
AR 2.94 (2.85-3.05), LR 1.65 (1.59-1.75).
Wing length 2.82-3.57 mm., width 0.68-0.88 mm., VR 0.95-1.05; squamal fringe 12-22; SCf on brachiolum 2-4.
Head: Frontal tubercles 15-51 x 10-18 µm, palpal proportions (µm) 51 (48-55) : 57 (50-60) : 213 (205-240) : 222 (205-235) : 345 (326-371).  Clypeus as wide as the antennal pedicel, with 19-24 setae.
Thoracic setae: acrostichal about 15 in double staggered row; dorsolateral about 14-26 in one to three rows; prealar 5-6; scutellar anterior row of 8-12 smaller setae, sometimes with abt 2 in a further anterior row, posterior row of 10-15 larger setae.
Legs yellowish, becoming darker on the tarsi.  Foretarsus without a beard.
Lengths (micron) and proportions:

 
Fe
Ti
Ta1
Ta2
Ta3
Ta4
Ta5
LR
F/T
Ta5/Ti
PI
1237
1137
1805
962
826
737
350
1.59-1.75
1.02-1.20
0.24-0.35
PII
1299
1176
734
399
291
185
139
0.51-0.53
1.06-1.17
 
PIII
1481
1449
1102
598
452
286
169
0.64-0.83
1.00-1.06
 
Sensilla chaetica: Mid Ta1 - 9,10; Hind Ta1 - 6,6.

Abdomen with dark oval markings on tergites II-IV or V, others light brown.

Superior volsella beaked, of D-type, between d and e of Strenzke (1959).  Setae of Inferior volsella forked.
About 19 setae on tergite IX.  The anal point does not appear to be darkened.

Pupa: Length 6.51 (5.99-6.61) mm in males, 7.21 (7.01-7.53) mm in females.  Colour brown, but pupal exuviae pale brown.  Frontal tubercles 75 µm long and 57 µm wide at base.  Thorax rugose, inner margin of wing sheath 1.69 mm long.

Fourth instar larva: A small to moderate plumosus-type (length (Fem) 12.2-13.5 mm).  Ventral tubules relatively long, anterior pair about 2.5 mm, posterior pair about 2.64 mm.  Anal tubules about 300 µm long.  Gular region and frontoclypeus slightly dark to dark over posterior 1/3 to 1/2, frontoclypeus darkened.
Mentum (Fig. c) with c1 tooth tall, c2 teeth well separated (type III), 4th laterals slightly reduced (type I-II).
Ventromental plates (Fig. d) with smooth anterior margin and about 38 (34-44) striae; VMR about 0.24-0.38.
Pecten epipharyngis (Fig. a) with about 12-16 broad sharp teeth(type B).
Premandible with outer tooth slightly longer and sharp, inner tooth blunt and about 1.5-2x wider.
Antenna (Fig. b) with basal segment about 3.4 (2.8-3.8) times longer than wide, ring organ about one third to 2/5th up from base; AR about 2.1 (1.97 - 1.79, segment proportions (microns) 118 : 29 : 9 : 11 : 6.
Distance between the antennal bases generally greater than that between the S4 setae.
Mandible (Fig. e) with 3rd inner tooth partly or sometimes almost fully separated,and partly darkened (type II-IIIB); about 13 (10-15) furrows on the outer surface at the base.  Pecten mandibularis with about 10 (9-12) taeniae.

Cytology: Four polytene chromosomes with the pseudothummi-cytocomplex combination BF, CD, AE, G.
Nucleolus subterminal in arm G, with a large BR about 1/3 from the other end of the arm.
Polymorphism in arms A, B, C, F and G: ArmC1 occurs in Varanasi while ArmC2 has been found at Jammu.

ArmA1:    1 - 2c, 4 - 9, 2d - 3, 12- 10, 13 - 19                                             as circumdatus A2, holomelas, ramosus
ArmA2:    1 - 2c, 10 - 12, 3, 14c - 13, 4 - 9, 2ed, 14d - 19                                             (India)
ArmB1:    Puff distal of centre of arm with dark bands distal.
ArmC1:    Large puff about the middle of the arm.
ArmC2:    Inversion of about two thirds of the arm                                             as ramosus
ArmD1:   
ArmE1:    1 - 2c, 8b - 6, 3 - 2d, 8 - 9, 4 - 5, 12a - 10, 12b - 13                 i.e. In5-9 and In9-3 from dorsalis (as ramosus)
ArmF1:    possibly 1 - 10, 15 - 11, 16 - 23     Nucleolus in about region 19                                             as halophilus
ArmG1:    prominent BR near middle of arm, another about 1/3 from paired end.

Chromosomes described by De & Gupta (1994), as C. niger, as Chironomus species 1 by Sharma et al. 1990), Chironomus plumosus form B (although it has no relationship whatever to C. plumosus) and incorrectly placed in the thummi-cytocomplex, and the similarly incorrect form A (Sharma et al. 2004) are very likely also this species.

Found:  India - Jammu & Kashmir: Kabeer colony, Jammu; Deoli Village; Farooq Nagar; Kabeer colony, Jammu; Bishnah wetlands;
            Gadhigargh; Sangrampur village; Univ. Jammu & Kashmir, Jammu.
            Japan - Kyushu: Nabikimatsu, Koge-Machi,Chikujyo-gun, Fukuoka Pref.;
            Ryukyu: Mt Omotodake, Ishigaki Cty, Ishigaki Island, Yaeyama Islands, Okinawa Prefecture.
            Malaysia - University of Malaya, Selangor (3.1295°N, 101.657°E) (BOLD)
            Pakistan - Islamabad (33.6863°N, 73.0763°E) (BOLD)
            Singapore - Bedok Canal.
            Thailand - Mahasarakham University, Kantharawichai District, Maha Sarakham Province (14.85°N, 103.26°E); Ban Tha Reu, Satuek
            District, Buri Ram Province (15.33°N, 103.56°E); Ban Keab, Kantharawichai District, Maha Sarakham Province (16.26°N, 103.22°E);
            Ban Khi, Chiang Yuen District, Maha Sarakham Province (16.27°N, 103.23°E).
Also:
            Israel - Mt. Hermon.
            Australia - Twin Falls, Kakadu Natl. Park, Northern Territory.

It includes some of those Indian samples (besides C. indiaensis) that have been classed as "C. samoensis" or "C. nr. samoensis".

DNA Sequence:
MtCOI: A sequence from Japan and several from India are in the data of J. Martin.
The sequence indicates that this species is quite close to the European C. alpestris, Goetgh.

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Revised: 26 September 2021
Access: Unrestricted
Copyright © 2011-2021, Jon Martin.