Palearctic Chironomus (s.l.) - Benthalia carbonaria

Benthalia carbonaria (Meigen, 1804)

Possible synonyms:
Benthalia dissidens (Walker 1856)
Benthalia dystenus (Kieffer 1916) - types in Hungarian Museum and hence lost
There are other possible synonyms, but they have not been recorded in the Oriental region.
The relationship of Oriental specimens to the described European species is currently unclear, to some extent because of the variety of names that have been applied to specimens (e.g. Einfeldia pagana, Einfeldia dissidens, Fleuria dissidens, Benthalia dissidens, Benthalia dystenus), but none seem to be synonyms of Benthalia carbonaria or B. dissidens and in the absence of types, the identity of B. dystenus is uncertain (see below).

In various BOLD Bins, but specimens from Japan, Korea or China are in BOLD Bins: BOLD:AAW3454; BOLD:ACB4917; and BOLD:ACD8351.
These are not the same BOLD Bins as the European specimens, suggesting the known Asian specimens are neither B. carbonaria nor B. dissidens (assuming these are not synonyms as assumed in Europe).

Since B. dystenus was described from Takao, Formosa, Kieffer's 1916 description as a species in Tendipes, is given:

11. T. dystenus
A dark reddish brown.  Vertex and the two frontal lobes brown.  Black brown palps.  Brownish antennae, of 12 segments, with tawny plume, articles 8-11 transverse, the first 2-3 times as wide as long, then less than twice, 12 segment 3 times as long as the previous ten combined. Shiny mesonotum, with traces of three darker bands.
White halteres, end of the club darkened.  Hyaline wings, transverse barely darker than the other veins, bifurcation of the posterior barely distal of the transverse.
Legs yellowish, 5 darkened tarsal segments, anterior metatarsus almost twice as long as the tibia, segments 2-4 not bearded, gradually slightly shortened, broad pulvilii.
Black brown abdomen, the last two segments enlarged and much wider than the segment which carries the forceps.  Tongue of the pliers (anal point) finished in point; terminal segments much longer than the basals, weakly arched, pubescent and with long sparse hairs, glabrous distal quarter, gradually slightly thinned, armed with 4 rigid bristles aligned at the end of the median side, these bristles at least longer than the width of the segment in the distal quarter, a shorter seta is located at the end of the article; superior appendages straight, cylindrical and pubescent, their third suddenly and strongly thinned, glabrous, exceeding the first fifth of the terminal article, curved in a hook at the end; inferior appendages reaching the middle of the terminal segments, straight, pubescent, a little thinner than the base of the superior appendages, terminal third enlarged in club and provided dorsally with long arched setae.
L. 5 mm.      Takao.

From this: AR about 3; LR almost 2; no foretarsal beard.
The description of the anal point as 'pointed' is not typical for a species of Benthalia and may indicate it being turned down so only the narrower basal part was visible.
This description is insufficient to reliably connect it with any of the presently known species.

This is one of the clear indications that several species are currently included under this name.

Adults: The adults of Japanese specimens were described by Sasa (1985b) as Chironomus (Einfeldia) dissidens, drawing on information in Sasa & Hasegawa (1983) - the larval mentum indicates that this is not the species in BOLD Bin: BOLD:AAW3454 (see below).

Description of Sasa (1985b):

Description of Adult from Kyushu:

Other probable species occurring in different BOLD Bins:

Description of Benthalia sp.2.

Description of Benthalia sp.3.

Description of Benthalia sp.4 from China.

[ Return to Index | Go to References ]