NORSK ENTOMOLOGISK TIDSSKRIFT - Norsk entomologisk forening

Investigations regarding the Plecoptera fauna in Rogaland 117
Summary
In systematic-ecological investigations 1960-65 of Plecoptera
fauna in flowing water in the lowland of inner Rogaland, \Vest
Norway, 14 of the 29 known Norwegian species were found.
Of these, one species has not been recorded south of Jonsvann,
South Tr~ndelag, 3 species are new to West Norway and 10 new
to Rogaland. None of the fourteen species has previously been
found in the localities investigated here. It was found that male
nymphs ready to emerge, can, in the case of several Plecoptera
species, be determined both by nymphal and adult characters.
Drawings of genetalia of adults and the nymphal characters of
some of the species, are shown in fig. 8 to 12.
The investigations comprise Suldalsl&gen in the District of
Suldal, and Sand, and Storelva and Fbgstadbekken in the District
of Sauda. The material consists of 62 adults and about 3600
nymphs. Of recent years, collections have been undertaken all
the year round.
Analysis of the material has shown that three species dominated
in the two rivers, namely, A. borealis with more than half
of all nymphs and, thereafter, L. fusca and D. nanseni. According
to Brinck, A. borealis and D. nanseni are the most common
species in North-Swedish rivers and, therefore, are suitable
for con~parison. A. sulcicollis, which is a more southern species,
has a stronger position in Storelva than in Suldalsl5gen. Differing
from the rivers, Fbgstadbekken has no species which dominates
in a similar manner; it diverges, further, in that only one of the
carnivorous species is found there.
Table 1. The plecopter association in Suldalsligen, Storelva and Fl0gstadbekken.
d = dominating, (more than 700 specimens): c = common,
(more than 30 specimens); r = rare, (less than 30 specimens).
Species
Suldals- Stor- Fl~lgstadlagen
elva bekken
Brachypiera risi .......................
Taeniopteryx nebulosa ..................
Protonemoura meyeri ..................
Amphinemoura borealis ................
- sulcicollis ..............
Nemoura cinerea. ......................
picteti .......................
Leuctrafusca ..........................
hippopus ......................
- nigra .........................
Diura nanseni. ........................
Isoperla grammatica. ...................
- obscura .......................
Chloroperla burmeisteri .................