The problems with Polypedilum Kieffer (Diptera: Chironomidae), with the description of Probolum subgen. n.
Author
Saether, Ole A.
Author
Andersen, Trond
Author
Pinho, Luiz C.
Author
Mendes, Humberto F.
text
Zootaxa
2010
2497
1
36
journal article
10.5281/zenodo.195747
c371f527-f7c6-456b-ab07-5bef541b10e6
1175-5326
195747
Polypedilum
subgenus
Polypedilum
Kieffer
Polypedilum
Kieffer, 1913
: 15
; not
Kieffer (1912: 41)
.
Kribiocharis
Kieffer, 1922
: 1
.
Pentapelma
Kieffer, 1921b
: 98
; 1921c: 33.
Rosenia
Kieffer, 1921a
: 275
; not
Waagen and Wentzel (1887: 943)
.
Propedilum
Lenz, 1937
: 13
.
Type
species
Polypedilum (Polypedilum) nubeculosum
(Meigen)
Chironomus nubeculosus
Meigen, 1804
: 18
.
Polypedilum emarginatum
Kieffer, 1913
: 16
.
The genus
Polypedilum
Kieffer
was described in 1913 and
Polypedilum emarginatum
Kieffer, 1913
[=
P. nubeculosum
(Meigen, 1818)
] designated as the
type
of the genus (
Kieffer 1913: 15
). As shown by
Ashe (1981)
, however, the
type
designation was invalid as two species were assigned to the genus
Polypedilum
in a paper published a year earlier (
Kieffer 1912: 41
). Of the two species,
P. pelostolum
Kieffer, 1912
and
P. ceylanicum
(
Kieffer, 1912
)
, at least the first according to
Freeman (1961)
is a synonym of
P. nubifer
and was selected as the
type
species. However,
Freeman (1961)
stated that
P. nubifer
is without frontal tubercles, while the presence of frontal tubercles is one of the most significant features of the species. Two
syntypes
of
P. pelostolum
from The Natural History Museum in London were examined. The specimens were lacking wings, antennae, hypopygia and most legs, but one head with frontal tubercles intact remained. Accordingly the synonymy with
P. nubifer
has to be accepted. As shown here
P. nubifer
, however, should be placed in
Tripedilum
. A case will be made to ICZN for rejecting the
type
designation of
Ashe (1981)
and maintaining the
type
designation of
Kieffer (1913)
.
Diagnostic characters.
The male imagines of the subgenus can be distinguished by having no frontal tubercles, bare wing membrane, wing vein R2+3 usually relatively well separated from R1, projection of superior volsella long compared to the short base and nearly always with outer seta and anal point never trifid or with lateral teeth or shoulders to each side of the anal point.
The few female imagines sufficiently described have nearly straight spermathecal ducts and the dorsomesal lobes of gonapophysis VIII are not reaching much caudal of the ventrolateral lobes.
The pupa has no frontal tubercles and no or vestigial cephalic tubercles, less than 20 branches in thoracic horn, single spur on caudolateral margin of segment VIII, taeniae on segments V and VI may be reduced in size or number and anal lobe without dorsal setae.
The larva has opposing Lauterborn organs; third antennal segment distinctly longer to somewhat shorter than fourth;
pecten epipharyngis
occasionally with less than 3 teeth in median scale, usually 3–5; mandible occasionally without dorsal tooth, usually with; occasionally mola smooth, usually serrate; mentum usually with first lateral teeth distinctly lower than second and median teeth, but often at least as high as median and/ or second lateral teeth; and ventromental plates without posterior lobes, with median apices pointing towards each other and distance between plates usually at least as long as combined width of 4 median teeth.
Remarks.
The pupae of
Polypedilum
s. str
. are not separable from those of
Pentapedilum
,
Uresipedilum
and
Probolum
. Most larvae cannot be distinguished from those of
Pentapedilum
. Some larvae, however, are separable from other known larvae except
P. (Pe.) epleri
Oyewo
et
Jacobsen, 2007
, by having first lateral teeth of mentum at least as high as median and/or second lateral teeth. From
P. (Pe.) epleri
they differ by either having mandible with a dorsal tooth, mola without serrations or well developed Lauterborn organs.