NORSK ENTOMOLOGISK TIDSSKRIFT - Norsk entomologisk forening

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Investigations regarding the Plecoptera fauna in Rogaland 113
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Fig. 14. Diz~ra nanseni (ICemp ny) A pronotum, B last abdominal segments
with the subgenital plate, C the last abdominal segments of the male.
(1900) and Bengtson (1933). The colour is dark brown with a
distinct pale median band on the pronotum (Fig. 14A). The
subgenital plate of the female (Fig. 14B) mostly resembles the
comnlon Swedish type (Rrinck 1949 s. 66). The male genitalia
Fig. 14C. The length of the male is about 12 mm, the female
about 14 mm.
Genus Isoperla Banks, 1906
Iso$erla gramnzatica (Poda, 1761).
Earlier records in West Norway: Ogna Ry (W.M.S.), Fana,
Fjelltveitvann, Bergen HOy (Kn), Lzrdal SFi (Kn).
Own records: Sauda and Suldal Ri. In all 11 nymphs were
found 317, 417 and 7/8-61. The nymphal characters are much
the same as described by Brinck, only the paler spots on the head
(Brinck 1949, Fig. 22A) were not always distinct, especially
in dark specimens ready for emergence. The white spots on the
dorsal side of the 5. abdominal segment were always visible.
The lancina with a single row of bristles; galea with fine hairs
on the inner side. Some male nymphs ready for emergence, with
skin partly split, were found on 4/7-1961. The skin was removed
and the specimens determined by means of adult characters,
which agree closely with Illies's description. Length 10-13 mm.
Isofierla obsczlra (Zetterstedt, 1840). (Brekke: I. venosa Stept.
I. grisefi~nnis Pict.).
Not found earlier in West Norway.
Own records: Sauda and Suldal Ri. In all 19 nymphs have been
found, the younger at 1013-65, the latest on 8/8-64. The
nymphs found on 2917 and 818 were ready for emergence.
The nymphs agree fairly well with Brinck's description; the
paler spots on the head were in most cases distinct, but the spots
on the 5. abdomen segment were not distinct in all specimens.