Chironomus (Lobochironomus) dorsalis (Meigen 1818)

Described from Japan as C. longipes Staeger, which is currently considered to be a synonym of C. dorsalis. However it remains to be clarified whether all specimens do belong to a single species.

Probable synonym: Einfeldia ocellata Hashimoto 1985.

The name Chironomus dorsalis was misapplied to a Chironomus (s.s.) species by Edwards (1929).  After re-examination of the type specimen (see below), C. dorsalis Meigen was placed in Einfeldia, but later recognized as a member of the new subgenus Lobochironomus of Chironomus by Ryser, Wuelker and Scholl (1985).
Epler (2001) did not accept the synonymy of C. dorsalis and C. longipes, considering that C. dorsalis was Einfeldia, but C. longipes was Lobochironomus.  However Spies and Sæther (2004) confirmed this synonymy.

In BOLD Bin: BOLD:AAW3454 as C. longipes.
However this appears to be a misidentification, as specimens in this Bin are a form of Benthalia (see Benthalia sp. 3)


Male terminalia of the type specimen of C. (Lobochironomus) dorsalis Meigen.
Drawn from the type specimen in the Paris Museum. (drawing courtesy of W.F. Wülker).

Adult (based on North American specimens as described by Townes (1945) as Tendipes (Einfeldia) dorsalis:

Male: Wing length 3.2 mm; LR 1.7; AR 3.0, frontal tubercles minute, fore tarsus without beard.
Pale green, with thoracic markings, etc., ochraceous; apical segments of tarsi brown;
abdominal tergites each with a central brown mark over most of the length of the segment,apical tergites entirely brown.

Female: Similar to male except for the usual sexual differences.

Pupa:

Fourth instar larva a medium melanotus-type (with small lateral projections and well developed VT).  Pecten epipharyngis with some thinner teeth interspersed between the normal teeth.

Cytology: (based on North American material) 4 polytene chromosomes with the thummi-cytocomplex combination AB, CD, EF, G.  Arm G with a subterminal nucleolus, a large BR just proximal to it and another BR near other end of chromosome.  Other nucleoli on arms B and D.
dlsA1:   
dlsB1:    Nucleolus (could be the BR found in other Lobochironomus species) near middle of the arm, typical bands 24-28 slightly removed
                from the centromere (region "X" of Ryser et al. (1985) reversed?).
dlsC1:    Large puff about one third from distal end.
dlsD1:    Nucleolus near the centromere.
dlsE1:    possibly 1 - 3c, 9 - 10a, 8i-a, 3ed, 10b, 5 - 7, 4 - 3f, 10c - 13
dlsF1:    Bands 8-9 about one third from centromere.

Found: Holarctic.  Type locality - Europe (France?); Denmark - (Type locality of C. longipes).
        Japan - (as C. longipes) - Wakaguri, Tsukuba, Kanto Japan (36.444°N, 140.083°E).

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Modified: 7 February 2020
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