Polymorphism And Taxonomic Problems In The Perlodes Microcephalus Group (Plecoptera: Perlodidae); Perlodes Mortoni Removed From Synonymy
Author
Zwick, Peter
text
Illiesia
2011
7
26
291
296
journal article
http://doi.org/10.5281/zenodo.4758218
2495e55e-efac-495d-afa2-c8c3f51bb78b
1854-0392
4758218
Perlodes microcephalus
(
Pictet 1833
)
Material examined.
Numerous
specimens from
Germany, Switzerland
,
Austria
,
North
and
South
Italy, Greece
and Anatolia were examined for egg structure.
Biometry
was additionally performed on the following:
Germany
:
Hesse
, upper course of
river Fulda
between Obernhausen and Ried
,
11♂
,
11♀
;
Hesse
,
Spessart
, tributary to
river Schmale Sinn
,
7♀
;
Lower Saxony
,
Harz Mts
,
Hohegeiss
,
1♀
;
Northrhine Westphalia
,
Albaum
,
2♂
,
1♀
(det.
J. Aubert
);
Baden-Württemberg
,
river Kocher
at
Gaildorf
,
2♂
,
1♀
;
Bavaria
,
Bavarian Forest
,
Rotbach
at
Böbrachmühle
,
3♂
.
Austria
,
Pongau
,
Eben
,
2♂
.
Switzerland
,
Hochrhein
at
Sargans
,
3♂
,
2♀
.
Turkey
,
Armenia
,
Pülümür Pass
,
3♂
,
1♀
;
North
Anatolia
,
Pass
between Terfenni and Korkuteli
,
1500m
,
8♂
,
13♀
.
Assigned
to
P. microcephalus
with doubt:
Germany
,
Lower Saxony
,
Medingen
,
8♂
,
5♀
.
Brachypterism
. Males range from strongly to barely brachypterous, several have a RWL similar to females. Wing length variation does not seem to be random but to occur stepwise. Should this be confirmed in larger samples the phenomenon might be related to number of larval instars through which specimens grew before metamorphosis.
Egg structure
. Sclerites on the anchor disc margin are well delimited and large. They are 2-3 times longer in radial direction than they are wide in peripheral direction. Sclerite orientation is oblique, sclerite tips point in a clockwise direction.
Variation between specimens from central
Germany
,
Italy
(Sila Grande), or
Anatolia
is normally not greater than between individual platelets of the illustrated specimen (
Fig. 5
). However, a female from N.
Italy
and one from
Greece
, Olympus, had shorter platelets.
Aberrant population.
A sample from N.
Germany
, Medingen near Uelzen, is assigned to
P. microcephalus
with some doubt. Variation of male wing length (
Fig. 2
) seems to resemble
P. microcephalus
but sclerites on the egg anchor are different between specimens and resemble some of the
P. mortoni
eggs shown in
Fig. 5.
A single female of
P. dispar
was taken at the same site.
Notes.
Types
of
Perla microcephala
are no longer available (
Zwick 1972
). I regard
Berthélemy (1964)
as first revisor in the sense of the
INTERNATIONAL CODE OF ZOOLOGICAL NOMENCLATURE
and follow his interpretation of the name.