New generic synomyms in the Chloropidae (Diptera, Acalyptratae), with additional taxonomic notes
Author
Nartshuk, Emilia P.
Author
Tschirnhaus, Michael Von
text
Zootaxa
2012
3267
44
54
journal article
10.5281/zenodo.208510
ec0b214a-a36b-4fa5-a6a8-2cc2a56196b4
1175-5326
208510
1.
Myrmemorpha
Dufour and
Elachiptera
Macquart
Dufour in 1833 described a brachypterous fly in the genus
Myrmemorpha
with a species
brachyptera
from
Spain
and included it within the family “athéricères” and tribe “muscides de Latreille”. The descriptions of the genus and species are rather short and are illustrated by the poor drawing of an antenna. The description of the antenna (composed from three segments) occupies three-quarters of the whole generic description. Dufour wrote that the insect looks like an ant or a small wingless ‘ichneumon’, but examination through a magnifying glass had assured him that the insect was a species of
Diptera
. Dufour placed the new genus not far from
Mosillus
in
Muscidae
[now in
Ephydridae
].
Macquart (1835)
considered the genera
Myrmemorpha
and
Elachiptera
separately, each containing a species with reduced wings, he placed
Myrmemorpha
after
Elachiptera
.
Afterwards
Schiner (1862
,
1864
) discussed the affinity of
Myrmemorpha brachyptera
and concluded that
Myrmemorpha brachyptera
is a fly known to him as
Elachiptera brevipennis
Meigen
and synonymized them. He assumed that Dufour had not seen the first segment of the antenna and wrongly had taken the arista as the third antennal segment. He repeated the generic synonymy in 1868 as well, using the corrected name
Myrmecomorpha
Dufour
(an unjustified emendation created by
Blanchard, 1840
). Further unjustified and identical emendations were used by many later authors, mentioning the taxon wrongly also with Dufour, Agassiz or Corti as authors.
Lioy (1864
: 1317–8) did not repeat the synonymy of
Myrmemorpha
Dufour
and
Elachiptera
Macquart
but included both separately in his family Heteromyziti, in which his subfamily Elachipterini is characterized by rudimentary wings. Lioy later (1895: 293) kept up this classification in his altered family-group taxon Elachipteri, subordered to his retained family Heteromyziti.
Bezzi (1900)
in his review on the phenomenon of wing reduction in
Diptera
accepted the synonymy of
Myrmemorpha brachyptera
Dufour
and
Elachiptera brevipennis
Meigen.
The genus and species of Dufour were listed in the Palaearctic catalogue in synonymy with
Elachiptera
Macquart, 1835
and
E. brevipennis
(
Meigen, 1830
)
, correspondingly (
Becker et al., 1905
). This catalogue repeated the synonymy which was already published (and later repeated) by
Schiner (1862
: 431; 1864: 231),
Neuhaus (1886: 295, 304)
,
Gobert (1887: 43)
and
Bezzi (1900)
.
Corti (1909: 141, 145)
in his revision of
Elachiptera
(as
Crassiseta
von Roser) and related genera considered
Myrmemorpha
Dufour, 1833
(as
Myrmecomorpha—
following the emendation of Scudder’s “Nomenclator”) as a valid genus and
brachyptera
Dufour
as a synonym of
brevipennis
Meigen.
Corti (1910)
in a long and detailed discussion cited personal opinions of Enderlein and Kieffer that structures of the antenna of
M. brachyptera
as described by Dufour are not similar to any species of Hymenoptera. Both his correspondents tended towards the considered synonymy of Dufour’s and Meigen’s brachypterous species.
Later
Becker (1909a)
devoted a special paper to the affinity of
Myrmemorpha
and
Elachiptera
after Corti’s publication. His conclusion was that Schiner’s opinion on the synonymy of
Elachiptera brevipennis
Meigen
and
Myrmecomorpha brachyptera
Dufour
was wrong, and Dufour’s insect probably was a species of Hymenoptera. Neither Schiner nor Becker had seen Dufour’s specimen(s). Becker’s opinion does not agree with Dufour’s words “Je le pris au premier coup d’oel pour une fourmi ou un petit ichneumon aptère … la loupe vint éclaircir tous me doutes et m’apprendre qu’il appartenait à l’ordre des diptères”. Nonetheless Becker accepted the similarity of
Myrmemorpha brachyptera
and
Elachiptera brevipennis
concerning colour and size. Later
Becker (1910)
repeated his opinion that
Myrmemorpha
Dufour
may not even belong to the
Diptera
.
Enderlein (1911)
,
Duda (1932)
and
Séguy (1934)
placed
Myrmemorpha
(as
Myrmecomorpha
Corti
) in synonymy with
Elachiptera
Macquart
, as Corti included in his genus only one species,
E. brevipennis
Meigen.
Sabrosky (1941)
included
Myrmemorpha
Dufour
in his “An annotated list of genotypes of the
Chloropidae
of the world …” as a doubtful genus citing the opinion of
Becker (1910)
.
Narchuk et al. (1970)
listed
Myrmecomorpha
Corti
in synonymy with
Elachiptera
Macquart.
Andersson (1977)
listed
Myrmecomorpha
Corti, 1909
with the species
brevipennis
Meigen
as a synonym of
Elachiptera
.
In the Palaearctic catalogue
Nartshuk (1984)
placed
Myrmemorpha
Dufour
in doubtful names.
Sabrosky (1999)
placed
Myrmemorpha
Dufour
as a questionable genus dubium in
Chloropidae
.
The first author failed to find Dufour’s specimen(s) in Paris in the collection of Muséum National d’Histoire Naturelle. She asked Dr J. Roháček and Dr R.H.L. Disney on their opinion if
Myrmemorpha brachyptera
may be a wingless species of
Anthomyzidae
or
Phoridae
and received negative answers. Species of
Scenopinidae
, which were mentioned by Dufour have another colour, usually black and white. By the way, Dufour distinctly wrote that
Myrmemorpha
belongs to
“muscides”
not far from the genus
Mosillus
,
but
Scenopinus
to “tanystomes”. It is necessary to take in account that the genus
Mosillus
was included in the family
Chloropidae
by
Schiner (1864
,
1868
). There exist only few European brachypterous fly species, size about 1 old French “ligne” (=
2.256 mm
) and coloured like described by Dufour, firstly
Elachiptera brevipennis
Meigen
and
Stiphrosoma sabulosum
(Haliday, 1837)
,
Anthomyzidae
. The antennae of the latter species bear long distinct pubescence excluding this species from attempt at an interpretation. A further tiny brachypterous European chloropid (for example occurring abundantly on very dry SE Austrian hills, coll. von Tschirnhaus),
Tricimba brachyptera
(Thalhammer, 1913)
and included until
1993 in
the synonymous genus
Crassivenula
Sabrosky
shows a certain colour variation: Light specimens in addition to their predominantly yellowish head and legs possess a lightened scutum with dark stripes. Also the partly swollen abdomen with its small dark or infuscated tergites within yellowish membranes appears predominantly light in such specimens. The species must be mentioned here to complete the possible range of species with a similar habitus.
The brachypterous polymorphic and tiny species of the genus
Stilpon
Loew, 1859 (Hybotidae)
must be discussed, of which 11 species occur in Europe and two,
S. graminum
(Fallén, 1815)
and
S. lunatus
(Walker, 1851)
, are recorded from the mainland of
Spain
(Carles-Tolrá, 2002), where Briviesca (Castil), the locus typicus of
M. brachyptera
, is located. The reason is that their antenna nearly exactly corresponds to figure 8 on the plate accompanying Dufour’s description of
Myrmemorpha
. In
Stilpon
spp. the first article is so short and hidden that it could not have been detected by Dufour through his magnifying lens. Thus, all former discussions in the literature on the so-called three-segmented antenna including the arista were superfluous. The second article (pedicel) is nearly ball like and bigger than the third one (1st flagellomere). It surrounds cap-like the basis of the 1st flagellomere. The arista inserts only slightly above the tip (supraapical) of the flagellomere and it is directed, alife, forwards and oblique outwards and slightly downwards (in Dufour’s fig. 8 it inserts at the very tip). All these details have never been discussed in the long disputes of the authors and correspondents mentioned above. Dufour correctly figured another antenna of a typical member of the Acalyptratae, “
Sepedon ferrugineus
” (
Sciomyzidae
), which shows that he was experienced in recognizing
Diptera
. He says that the use of his lens dispelled all his doubts if it was a member of the order
Diptera
. His funny report on his insect collecting during his dangerous military service focused on the “singularité” of this antenna, he knew “no genus in the long series of
Muscidae
” [translated from French] with such a configuration. A further interesting detail never was discussed: Dufour characterized the fly as “il courait avec assez d’agilité et sautillait parfois” (it ran very agil and sometimes it jumped). Just this behaviour “moving running or jumping” (“… bewegten sich laufend oder hüpfend”) was published by
Joost (1991)
and was also observed by the second author in a
Stilpon graminum
(Fallén, 1815)
population feeding on Collembola on the ground of a
Carex
swamp in Bielefeld,
Germany
.
Contradicting details in Dufour’s description are [as translated]: 1) “Head plane like
Oscinis planifrons
”;
Musca planifrons
Fabricius, 1798
was transferred to the genus
Platycephala
Fallén
in the year 1820 and it is one of the largest European species of
Chloropidae
with a punctured and completely different frons than
Stilpon
spp. or
Elachiptera brevipennis
. Contrary, the frons of
Stilpon
spp. are narrow, slightly dusted but still shining; because the head is ovoid the frons is not outspread in a peculiar plain. 2) Length “
1 lig[ne]
” =
2.256 mm
, contrary,
Stilpon
spp. measure only 0.8 up to 1.6 mm, but Dufour’s measuring during military service could have been only an estimate.
Dufour’s description
“Rufa, nitida, scutello abdomineque nigrescentibus; alis abdomine triplo brevioribus”
corresponds well with the shining red-brown
E. brevipennis
and its darker hind parts (compare
Fig. 9
, this article). Dufour’s figure of the antenna corresponds relatively well with a
Stilpon
species. Both species occur together in one habitat (caught together by the second author). Dufour said that [translated] “the tussocks were populated by myriads of small insects”. We must assume that the author mixed up both species for his description. The appropriate Latin description is here accepted for
E. brevipennis
, the more or less correct figure for a
Stilpon
species is neglected here, as well the jumping behaviour. In the nature the first author observed small jumps in
E. brevipennis
, too.
As
also
Stilpon
spp. are jumping we have a cast iron proof that Dufour’s observed insects could belong as well to the chloropid as to the hybotid species. These results clarify all published doubts of the past.
The puzzling last sentences of Dufour, comparing his new genus with the dissimilar genus
Scenopinus
Latreille, 1802
can now be intepreted better, presuming that also a
Stilpon
species must have been included in his material. He correctly placed one of his mixed up fly species in a group of more basic "
Muscidae
", nearer to the more plesiomorphic genus
Scenopinus
.
This genus also possesses slightly shortened wings and a rudimentary arista arising from the tip of the first flagellomere.
As
the older name
Myrmemorpha
and its emendations had not been used (except in catalogues and lists) since
1899 in
at least 25 works published by at least 10 authors in the last 50 years and encompassing a span of not less than 10 years this case is excluded by the ICZN, articles 23.9.1, 23.9.2, and 23.9.3, from involving the Commission. It is not available.
We compare the description of
Myrmemorpha brachyptera
with specimens of
Elachiptera brevipennis
and agree with Schiner that Dufour wrongly interpreted the arista as the third segment of the antenna. Therefore we consider these species as being synonyms. We add all other synonyms and their misspellings and emendations of
Elachiptera
, too. The six generic synonyms in
Cherian (1975)
are repeated opinions or errors from the literature and they are not discussed and partly not accepted here. A formal listing of
Elachiptera
and its synonyms is presented here: