o .eg an Jo of En1tomol0lD' - Norsk entomologisk forening

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Fig. 4. Abundance of Noctuidae species constituting
more than I % of the light trap catches in the Cat/una
heath at Austre Loftmyra in 1978.
ometridae, indicates that the ranking of the dominant
species in the two habitats is more simi­
• lar in Geometridae than in Noctuidae.
The dominant species
The ranking of the dominant Geometridae in the
heath and on,the grassland is shown in Figs. 2
and 3. Thera cognata (Thunberg, 1792) was the
dominant species in both habitats, constituting
54% and 43% of the Geometridae in the heath
and on the grassland, respectively. T. juniperata
(L., I758) ranked as no. 2 (8 %) on the grassland.
The species has a late flight period (see below),
and as the trapping in the heath had to be terminated
in September the species was not taken in
this locality. Catches from other heath localities
indicate, however, that the species also would
have taken a dominant position in the material
from this locality if the trapping had been continued.
Both species are common and widespread
in Western Norway.
In the heath Eulithis testata (L., 1761) ranked
as no. 2 (7 %), Pachycnemia hippocastanaria
(Hiibner, 1799) as no. 3 (6 %), Eupithecia pusillata
(Denis & Schiffermiiller, 1775) as no. 4
(6 %), and Gnophos obfuscata (Denis & Schiffer­
Fig. 5. Abundance of Noctuidae species constituting
more than I % of the light trap catches on the grassland
at Austervagen in 1978.
muller, 1775) as no. 5 (5 %). E. testata and E.
pusillata are common and widespread in Western
Norway. P. hippocastanaria is common in
the coastal heaths, and single specimens have
also been taken in the middle part of Hordaland.
G. obfuscata is common in the lowland in the
innermost part of Western Norway, but seems
more or less to be absent from the middle part of
Hordaland.
On the grassland Eulithis populata (L., 1758)
and E. testata ranked as no. 3 and 4, both constituting
about 6% of the material, while Perizoma
didymata (L., 1758) ranked as no. 5 (5 %).
The species are all common and widespread in
Western Norway.
The ranking of the dominant Noctuidae in the
two habitats is shown in Figs. 4 and 5. Lycophotia
porphyrea (Denis & Shiffermiiller, 1775) was
the dominant species in the heath, constituting
30 % of the material. On the grassland Cerapteryx
graminis (L., 1758) ranked as no. I (I5 %).
Many places in Europe this species is a feared
pest, appearing in high numbers at irregular intervals
(e.g. Entwistle and Rivers 1974). Both
species are common and widespread in Western
Norway.
Amphipoea lucens (Freyer, 1845) ranked as
95