Asian Chironomus: C. flaviplumus Type A

C. flaviplumus sensu Sasa (Type A)

This variant was described by Sasa (1978). This is more likely to be C. flaviplumus sensu Tokunaga as it was collected in northern Japan and has the higher AR.

Sasa lists important features as the AR of 3.5-4.0; LR of about 1.6-1.8 and the relatively long anterior Ta5, which is about 0.35-0.4 length of anterior Ti.
In a later paper, Sasa and Hasegawa (1983) give a much broader range of values (including Ta5/Ti values of only 0.25) and synonymised C. flaviplumus with C. samoensis. However it is more likely that they had a mixture of species.

This species is in BOLD Bin: BOLD:ACQ8383.

Adult:

Male: AR about 3.5-4.0.
Color: Antenna with yellow hairs; thorax pale yellow to yellowish green, scutellum yellow, vittae and post notum orange yellow.  Leg segments largely yellow brown, some darkening at distal ends of tibiae annd tardii, with Ta5 almost entirely dark.
Head: Frontal tubercles about 33-39 µm.  Palp proportions: 44 : 53 : 189 : 222 : 315; P5/P4 1.42, P5/P3 1.65.
Thoracic setae not recorded
Wing length: 2.85-3.15 mm; wing width 0.30-0.67 mm., VR about 1.0.  Wing milky white with crossvein dark.
Leg lengths (microns) and proportions as follows:

	Fe	Ti	Ta1	Ta2	Ta3	Ta4	Ta5	LR	F/T	BR
PI	1390	1240	2030	1020	930	880	500	1.63	1.12	2.1
PII	1460	1290	810	460	340	190	130	0.62	1.31
PIII	1660	1660	1240	660	490	280	175	0.75	1.00

Ant Ta5/Ti - 0.40.

Abdominal tergites II-IV with a dark central oval spot, tergites V-VIII almost uniformly dark brown. Setae on 9th tergite: 9-12.
Superior volsella "beaked". Gonostyle reduces relatively sharply at about half way.

Female
Head: Antennal proportions (micron): 180 : 130 : 140 : 140 : 250.
Frontal tubercles about 26 µm long and 12 µm wide.
Palp proportions (micron): - : 60 : 250 : 250 : 370.
Thorax coloration as in males.
Wing length: 3.5 mm; wing width 1.1.
Leg lengths (microns) and proportions as follows:

	Fe	Ti	Ta1	Ta2	Ta3	Ta4	Ta5	LR	F/T	BR
PI	1510	1220	2150	1170	1100	1100	510	1.76	1.24	0.90
PII	1540	1370	830	440	340	200	140	0.61	1.12
PIII	1660	1610	1220	660	500	290	200	0.76	1.03

Abdomen largely brown, except for a pale area posterior on segments II-VI; II and III with a broader band, with an extension of the brown area in the midline. No information on segment X or the cercus.

Pupa: Exuvia length about 7.8 mm (Males 7.0-7.5 mm). Caudolateral spur of segment VIII commonly with 3 spines, but range from 1-5 (Sasa 1978).

Fourth instar larva: a medium sized plumosus-type larva (length about 14.0-14.8 mm.). Anterior ventral tubules (1.14-1.20 mm.) shorter than posterior pair (1.40-1.52 mm.). Anal tubules long and cylindrical, about 250-320 &$181;m, about 2.3-3.2 times longer than wide, ventral pair possibly slightly shorter and thicker (260 x 100; 250 x 110 µm). Gula pale or very slightly darkened on posterior third; frontoclypeus pale.
Mentum (Fig. b) with square sharp teeth, c2 teeth of central trifid tooth well separated from c1 tooth (type III), 4th laterals slightly reduced (type I-II).
Pecten epipharyngis (Fig. a) with about 16-21 variable but sharp teeth. Ventromentum (Fig. c) with about 29-36 striae; VMR 0.27-0.38.
Antenna (Fig. d) with a moderately long basal segment, which is about 3.5-4.5 times as long as wide; RO about a third to 2/5 up from base; AR about 1.75-2.0. Antennal proportions: 115 : 30 : 10 : 12 : 6.
Distance between antennal bases possibly greater than that between the S4 setae.
Mandible (Fig. e) with third inner tooth only partly darkened and separated (Type I-IIB), and with about 12-14 furrows on outer surface at the base; about 10-12 taeniae in Pecten Mandibularis.

Cytology (based on material studied by Wuëlker et al. 1989 and unpublished): 4 polytene chromosomes with the pseudothummi arm combination AE, BF, CD, G. Nucleolus virtually terminal in arm G; well developed BR about one third from the other end, and a smaller BR close to this other end; closely paired. A nucleolus also occurs near the characteristic bands of arm F. Arm A of Australian C. "orientalis" differs from that of this species by a complex inversion, and arm F by possibly a simple inversion.
Polymorphism in arms C and G.

flaA1: 1a-i, 2k-d, 9e - 4a, 13a - 14i, 3h-i, 12c - 10a, 2c - 1k, 3a-g, 15 - 19 (Japan)
flaB1: Puff with distal dark bands (groups 8-7?) about the middle of the arm
flaC1: Characteristic band groups 3-4 about one quarter from distal end.
flaC2: Differs by a small terminal inversion, distal of characteristic band groups 3-4.
flaD1:
flaE1: 1 - 3e, 10b - 3f, 10c - 13 as halophilis, etc.
flaF1: 1 -2a, 10d-a, 15 - 11, 2b - 9, 16 - 23
flaG1: Virtually terminal nucleolus, two BRs as noted above.
flaG2: Simple inversion of most of the chromosome, bringing the large BR close to the nucleolus.

Chromosome arms A, E and F were described by Wülker et al. (1989) as C. samoensis. However, some sequences of Australian specimens is not the same, although closely related.
Indian specimens described by Chattopadhyuy et al. (1991) also do not appear to be the same species, as the LR is reported as 1.4; the ant. Ta5 is only about 0.25-0.28 length of Ti, and the frontal tubercles are only about 18-25 micron. The Indian material is also cytologically distinct. However the mtCOI sequence is very similar to those of C. flaviplumus Type B, and a specimen from Bishnah wetlands, Jammu and Kashmir is particularly close.

Important features are the central oval spots on abdominal tergites II-IV, the LR of about 1.8-2.0 (though known range of the possibly multiple species: 1.6-1.8) and the relatively long anterior Ta5, which is about 0.35-0.4 length of anterior Ti.

Found: JAPAN - NEIS and Hanamuro, Tsukuba; Minitoku, Tokyo; Ohta River, Hiroshima Prefecture. Ryukyu: Mt Omotodake, Ishigaki City, Ishigaki Island, Yaeyama Islands, Okinawa Prefecture.

Molecular Sequence:MtCOI: Sequence for these specimens is in GenBank (accession numbers AB740235-9), the BOLD Database and the Japanese Chironomid Barcode Database - often identified as C. flaviplumus, but as noted above, the identity of the true C. flaviplumus has yet to be confirmed.

See also C. circumdatus, C. "orientalis", C. indiaensis, C. nr. flaviplumus, C. ramosus.

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