NORSK ENTOMOLOGISK TIDSSKRIFT - Norsk entomologisk forening

New Records of Capnia bifrons (Newman)
at Tynset in Hedmark (Plecoptera, Capnidae)
By A. Lillehammer
Zoological Rluseum, University oi Oslo
The records of Cnptzin bijro4z.s newm man 1838) at Tynset are
the northernn~ost known in Scandinavia (fig 1). Earlier we have
only records of C. bifrons, with specimens from Oslo and Bzrum
in Norway and from the south and west of Sweden.
Descri$tion of the Hiotops: Tynset is situated in the northernmost
part of Hedmark, North Osterdal, where the mountain bedrock
mainly consists of phyllite laminated by gneiss and gabbro.
The height above sea level is about 490 m at Tynset railway station.
The river Glomma meanders along the valley bottom. Large
parts of the valley are cultivated. Tynset is a mountain district
where the climate is hard; snow frequently falls towards the end
of October and lies well out into the spring. The parish lies within
an area where there is little prec,ipitation (Ahlman 1925). Tlle
mean temperature is about - 12" C in January whereas in July
it is between 12" and 13" C (Birkeland 1936).
C. bifro~zs were found in three streams; Skytterbanebekken,
Storbekken and Kaldbekken, arid in the river Tanna, all of
them debouching into the river Glomma (fig. 2). Tanna and
Kaldbekken were only causally explored and the invcstigatioris
were concentrated upon Skytterbanebekken and Storbekken
where the snow lay deep along the banks and only a few single
areas of stream were bare of snow and ice. Both streams emanate
from a forest area in the mountains, and flow through cultivated
fields. Similarly, as in Sztcrbekken (Lillehammer 1965),
a considerable amount of foliage and other organic remnants,
was found between the stones. Foliiferous trees fringe the stream
course, but along Skytterbanebekken the trees had just been
fcllcd. In Skytterbanebekken the pH was 7.0, dissolved in water
25.4 mg CaO/l was measured. In Storbekken the pH was 6.8,
dissolved 16,3 mg C,aO/l was measured. The nleasurements of pH
were made electrometrically.