Full-text - Norsk entomologisk forening

Norwegian stoneflies II 233
forest areas, and in northern Norway it occurred
also in the Sub-Alpine vegetation
belt. In Sweden the species was taken both
in the southern and northern parts, but mainly
in southern streams (Brinck 1949).
Isoperla grammatica (Fig. 31) is the most
common of the Isoperla species. In the south
it was taken both in coastal areas and at high
altitudes (1100 m a.s.l.). It inhabits small
streams, temporary or permanent, large
streams and rivers. The species has not been
taken in lakes. It does not occur above the
Sub-Alpine belt, being common in the Boreal
coniferous forest areas. In Sweden it was
taken in all parts of the country (Brinck 1949).
Isoperla obscura (Fig. 32) was taken in all
parts of the country. In northern Norway
the species has been found in small and large
streams, rivers, lakes and lake outlets. In the
coastal areas the species is rare. In southern
Norway the species occurs in all types of
freshwater in the central mountain areas where
it was taken up to 1465 m a.s.l. It was seldom
found in the lowlands where it is restricted
to large streams and rivers, but it has been
taken as far south as below 0yeren in the
Glama watercourse, Akershus. In the west it
is most common in the mountains, only occurring
in large streams in the lowlands and
then only in inner fjord areas.
In some areas Isoperla obscura seems to
occupy a wider spectra of habitats than elsewhere.
These are the North 0sterdalen area,
the mountain areas of 0vre Heimdal and the
areas of Kautokeino and Pasvik. Isoperla
obscura was taken both in northern and
southern Sweden, but according to Brinck
(1949) the species is eucoenic in northern
rivers.
Fam. Perlidae
The carnivore Dinocras cephalotes (Fig. 33)
was found in scattered localities from Telemark
in the south to Finnmark in the north.
Most of the records are from the central
mountain areas of southern Norway where
it was taken in small and medium-sized
streams, largely in the Boreal pine forest
zone, although it has also been taken in the
Sub-Alpine belt (1090 m a.s.l. in 0vre Heimdal).
In the west the species has been taken
twice in Rogaland. In the north nymphs have
been taken in Anajokka near Kautokeino.
This is the northernmost record of this species.
In Sweden Dinocras cephalotes was not
taken in the northernmost parts and it has
not hitherto been recorded from Finland.
Fam. Chloroperlidae
In this family there are only two species, both
omnivorous. Xanthoperla apicalis (Fig. 34)
has been taken at scattered localities in the
boreal forest areas in southern Norway, once
in northern Norway and not at all in western
Norway.
Siphonoperla burmeisteri (Fig. 35) occurs
in all types of freshwaters in southern Norway
in the boreal coniferous forest area up to
the Sub-Alpine. In Sauda it was once found
in the lowest part of the Sub-Alpine belt.
The highest locality is at Mellsen in 0ystre
Slidre at about 1000 m a.s.l. in the upper
part of the coniferous forest belt. It is common
in the west, including the coastal areas.
In the north it has been taken in small and
large streams, rivers and lakes in the pine
forest area of Pasvik, where it is common.
Outside this area it is more scarce. The species
was taken both in northern and southern
Sweden and is, according to Brinck (1949),
eucoenic in northern streams.
Fam. T aeniopterygidae
In this family there are two species, both
herbivorous. T aeniopteryx nebulosa (Fig. 36)
has been taken in all parts of Norway, but
is absent in the coastal lowland areas of North
Rogaland and Vestfold. It occurs at all heights
up to about 1200 m a.s.l. in the Low-Alpine
belt. The species may be common and numerous
both on stable stone substrata covered
by moss and algae and in streams with a sand
bottom and silting. It is found in all types
of biotopes, except lakes, although it may be
very common in outlets. The species has been
taken both in northern and southern Sweden
(Brinck 1949).
Brachyptera risi (Fig. 37) has also been
taken in all parts of Norway, but in Troms
and Finnmark only in the fjord and coastal
areas. In southern Norway it was taken in
the outerm08t coastal areas of both North