Fróðskaparrit - 01.07.2004, Blaðsíða 48

46
WETLAND COLEOPTERA OF THE FAROE ISLANDS
(1930) reported one specimen from Ljósá
south of Tórshavn. In June 2004, we found
it in 20% of samples. This species was con-
fmed to extremely shallow water with
mosses, avoiding areas of water movement
when in gullies and springfed mires. The
females were of the male-like form, as is
typical of much of Scotland, with the matt
female form castaneus Aube occurring
only in the southem Border areas.
Hydroporus nigrita (Fab.). West (1930)
reported only one specimen, found at Tór-
shavn. H. nigrita was common in shallow
flushes in June 2004, being found in 30%
of all samples. The nigrita-species group
has recently been reviewed by Shaverdo
(2004). The status of H. nigrita as the com-
monest Palaearctic member of the group is
confirmed, being found everywhere includ-
ing Iceland and most Iberian mountain
ranges, confined in the east to east Siberia
and Kazakhstan. It can occur up to 2,500 m
above sea level, but is more common in
lower areas.
Hydroporus palustris (L.). West (1930)
noted four records, but could give details
only for Borðoy and Eysturoy. It occurred
four times in June 2004. One of the locali-
ties, a pool named Nykutjørn, was unusual
in having a thin cover of bogbean (Menyan-
thes trifoliata L.) throughout, and is the
only known Faroese site for white water
lily (Nymphaea alba L.). There the H.
palustris were of the pale form that once at-
tracted specific status as tinctus Hamlet
Clark. These specimens had an entirely yel-
low head and a pronotum similarly colou-
red with a narrow dark mark on much of the
hind margin. However, all specimens had
the typical elytral pattern obscurely
marked.
Hydroporus pubescens (Gyllenhal). Most
earlier authors have commented on the
abundance of this species on the Faroes.
Despite the occasional occurrence of pale
specimens, this species has not attracted
other names in regular use. We found it in
60% of samples, usually as the commonest
species in still water, and in abundance in
saltpans and peat pools.
Stictotarsus multilineatus (Falkenstrom).
Sharp (1900) recorded Hydroporus gri-
seostriatus as being taken by N. Annandale
near Tórshavn in June 1900, the first
Faroese record according to Reuter (1901).
West (1930) added records for Vágar,
Streymoy, and Borðoy, mainly in montane
lakes. In the survey in June 2004 it was
found only four times.
Unfortunately the name of this species
has changed considerably and is not yet se-
cure. Falkenstrom (1922) described the var.
multilineatus for what was then known as
Potamodytes griseostriatus (DeGeer), hav-
ing previously been described within Dytis-
cus, transferred to Hydroporus, and then to
Deronectes and Potamonectes. Subse-
quently the specific status of multilineatus
was recognised by Nilsson and Holmen
(1995) on the basis of chromosome studies,
with it being most widespread species in
the north-west of Europe, and the species
occurring in Shetland and the Faroes. The
change of specific epithet came soon al'ter a