Fróðskaparrit - 01.01.1999, Side 159

FRÁBOÐAN UM TVEIR FERÐANÁTTVIRVALDAR
AGROTIS SEGETUM (L.) OG NOCTUA ORBONA (Hfn) (LEPIDOPTERA, NOCTUIDAE)
163
Table I. Day to day changes in meteorological factors over the Faroe Islands during periods in 1996 and 1997
with long-range lepidoptera migrations.
Talva 1. Veðurlagsbroytingar í 1996 og 1997 við nógvum ferðandi náttfirvaldum.
Temperature values, wind direction and wind velocity at sea level are recorded at midnight, 00 UTC, and at
850 hPa (1500 m above sea level) at 12 UTC. Datafrom Deutsche Wetterdienst, Frankfurt am Main.
Meteorological Data at Sea LeveData at 850 hPa (1500 m a.s.l)
Year/ Observation Pressure Temp. Wind Velocity Temp. Wind Velocity
date of migrants (hPa) (°C) direction (m/sec) (°C) direction (m/sec)
1996:
12.VI - 1005 +9 w 15 0/-3 nw 20
13. VI - 1025 +7 n <5 +1/ -6 w 10
14.VI + 1030 +10 ssw 10 +3/+1 w 20
15.VI - 1025 +10 w 5 +9/-14 sw 20
16.VI + 1025 +9 e < 5 +5/-1 sw 30
17.VI - 1010 +9 nw 10 +1/ 0 nw 30
18.VI + 1015 +8 ne 20 +3/ -7 nne 25
19.VI + 1020 +8 n 5 0/-2 n 15
20. VI + 1020 +6 ne < 5 +1/-20 ne 20
21.VI + 1020 +5 nw 5 +2/-20 n 15
1997: 28.VI 1020 +5 w 5 +7/-27 nw 5
29.VI - 1015 +5 w >5 +8/-10 n 5
30. VI - 1012 +5 ne 5 0/ -7 ne 25
l.VII - 1015 +7 nw 15 +2/-25 ne 30
2.VII + 1015 +8 ne 10 +7/+1 e 15
3.VII + 1010 +8 ne 5 +2/+1 se 20
4. VII + 1010 +9 s 10 +4/-11 sw 20
5. VII + 1015 +10 sw 5 +7/+4 w 30
however, was more distinctly marked and
had a differentiating light brown ground
colour. During the winter, the specimen
was handed over for determination to an-
other Faroes lepidopterist, Mrs. Annleyg
Patursson in Tórshavn. During a visit in
early August 1998, the specimen was
shown toSK who identified it as Noctua or-
bona (Hfn.), another unrecorded moth
species from the Faroe Islands. At that
time, the specimen had lost its abdomen,
which complicated to some extent a deter-
mination of sex, as the species, contrary to
N. pronuba, does not demonstrate sexual
dimorphism in forewing coloration. The
coupling site of the frenulum on the under-
side of the forewing demonstrated that it
was a female, cf. Fig. 39-C in Kristensen
(1970). The appearance of Noctua orbona
compared with N. pronuba is shown in Fig.
3.
The occurrence of N. orbona in the Faroe
Islands was unexpected, as the moth until
now had not been regarded as migratory.
The record occurred contemporaneously,
however, with other regular migrating lepi-