Fróðskaparrit - 01.01.1999, Page 157

FRÁBOÐAN UM TVEIR FERÐANÁTTVIRVALDAR
AGROTIS SEGETUM (L.) OG NOCTUA ORBONA (Hfn) (LEPIDOPTERA, NOCTUIDAE)
161
Danish entomological meeting in March
1998, SK was informed about the finding.
Agrotis segetum had not been recorded
previously in the Faroe Islands, but is a
well-known straggler, recorded both in Ice-
land and Shetland. Therefore, it could be
anticipated to be in the Faroes, especially in
a year like 1996, which was a year of strong
migrational activity by many migratory Eu-
ropean lepidoptera (Kaaber, 1997a). The
specimen was recorded during a period in
June during which several common migra-
ting lepidoptera, e.g. Vanessa atalanta and
Autographa gamma, and also a few V. car-
dui were observed in the Faroes. In a simi-
lar year, in 1995, which also exhibited
much migrational activity in the Faroes, the
first Iceland specimen was captured in a
light trap at Kvisker on 20 August in the
southeastern part of the country (Olafsson
andBjomsson, 1997).
The two records are the northernmost
sightings in Europe. In westem and central
Europe, the moth occurs quite commonly
in England and southeastern Scotland
(Bretherton et al., 1983). It is well distrib-
uted in Denmark and the southem parts of
Scandinavia, while in Norway, it is only
resident in the southemmost section of the
country (Nordstrom et al., 1969; Skou,
1991).
North of its residential area in Great
Britain, such as the main part of Scotland
and the Orkneys, it is recorded irregularly
and without any evidence of breeding
(Lorimer, 1983). In Shetland, the moth has
been recorded singly on eastem Mainland
at Eswick, the first time in July and Sep-
tember 1994 and then again in September
1995. In 1996, it was recorded there singly
in both June and late August. No records
were made in 1997, but one was made in
early July 1998 (Pennington, 1996; 1997;
Pennington and Rogers, 1999). The many
recent records from Shetland seemingly
represent only stray specimens from Conti-
nental Europe.
In Denmark, A. segetum is a moth
species of considerable economic impor-
tance. The larvae, as cutworms, often da-
mage various agricultural crops. The moth
has been surveyed over the last forty years
and strong annual fluctuations in its fre-
quency have been noted. During the peri-
od, however, no firm evidence of any regu-
lar migratory behaviour in Northem Eu-
rope has been established, contrary to
southwestem Europe where the moth is a
regular migrant (P. Esbjerg, personal infor-
mation). Migrations from the latter area
have been traced in southem England as
early as early May, where the moth has
been recorded together with other Mediter-
ranean moth species (Hale and Hicks,
1999).
The appearance of the moth can be con-
fused with two other related migrant
species found in the Faroe Islands, namely
Agrotis ipsilon (Hfn.) and Peridroma
saucia (Hb.), which also have pearly hind-
wings, Fig. 2. Both are usually larger than
A.segetum. On the forewing, A. ipsilon has
a black dash extending from the reniform
stigma to the outer cross line; in P. saucia,
this black dash is lacking, but the forewing
markings, especially the innermost orbicu-
lar stigma, are larger, the forewing is broad-
er and of a more mottled brownish colour,