NORSK ENTOMOLOGISK TIDSSKRIFT - Norsk entomologisk forening

11. Investigation of the surface after the
culmination of a flood on the Gaula.
Mostly only Carabid beetles were collected.
Samples H-1 (Table IV), Station 3, 10 June
(11-1, A) and Station 7,12 June 1965 (11-1, B):
In tree zone 2, the flood had deposited large
amounts of twigs and leaves, among which the
Coleoptera were found. Silt mixed with humus
-normally loose and porous, but compact by
the time of the investigation. The site on
Station 7 was also investigated 23 June, but
Carabidae were not found.
Samples 11-2 (Table IV), Stations 6 and 7,
12 June 1965: Rather elevated, more or less
sunny spots with fine sand-silt mixture and
little or no vegetation. Sample 11 -2, A, from
above bare, sandy and gravelly places, the
sample on Station 7 from just above open,
silty places in the bush zone.
THE EFFECT OF INUNDATION
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Sample 11-3 (Table IV), Station 1, 14 June
1965: The water level had dropped considerably
and small refuges (some square metres),
surrounded by the river, appeared in the bush
zone. The sand was saturated with water.
Ill. Material collected in the river or
from trees or trunks isolated in the river
Sample 111-1 (Table V), the Gaula, Station
3, 14 June 1965: The material had been in the
river for nine days or more. The volume of
the material about twice that of sample 111-2.
Sample 111-2 (Table VI), Rundhaug, 2 June
1967: The material had been in the river for
only a few hours. Weight of dried and sieved
material 50 g. The only arthropods occurring
numerously were Collembola.
The material which had been in the river
for days was much richer than that which had
Table IV. Number ofspecimens ofColeoptera collected in Samples 1I-1-3 by time-catch
Sample
Collecting time (mins.)
Nebria gyllenhali Schnh.
Dyschirius angustatus Ahr.
Asaphidion pallipes Dft.
Bembidion argenteolum Ahr.
B. bruxellense Wesm.
B. femoratum Sturm
B. lapponicum Zett.
B. litorale 01.
B. lunatum Dft.
B. petrosum Gebl.
B. quadrimaculatum L.
B. saxatile Gyll.
B. schueppeli Dej.
B. semipunctatum Don.
B. virens Gyll.
Trechus secalis Payk.
Calathus melanocephalus L.
Agonum assimile Payk.
A. micans Nic.
Ancyrophorus omalinus Gyll.
Brachyusa concolor Er.
Tachyusa leucopus Mrsh.
Psammodius asper Fabr.
11-1, A
40
2
13
11-1, B
40
3
3
41
2
2
1
11-2, A
15
1
4
4
13
11-2, B
3
7
7
4
2
11-3
2
2
1
1
23
13
1