1938 - The Vasculum

19
MIGRANT LEPIDOPTERA IN 1937.
F. C. GARRETT.
The year 1937 has been a poor one for lepidoptera and most
species have been scarce throughout Europe, the migrants being particularly
so, but some very interesting observations have been made. For long it was
believed that migration to the British Isles was one-way traffic, that swarms
came over from the Continent, but that there was no movement from this
country southwards, but it is certain, now, that numbers of migrants do
leave for France, though it is not certain whether this occurs regularly or
only occasionally. Mr. A. W. Godfrey reported from the Start Lighthouse
that on August 28th "thousands of Plusia gamma passed in steady flight
going due south, at an elevation of 200 feet," and he found about fifty
specimens round the lantern (Entomologist, lxx, page 229), and there were
other cases.
Pieris brassicae-The Large White. Many great swarms were
reported from the Continent, several reached the South coast, and
throughout the country it was abundant. Mr. W. Wannop wrote from
Bamburgh: "On July 1st I was in the bathing hut, to the north of the Castle,
where I saw hundreds of white butterflies just landing, on a frontage of
about two hundred yards. It was quite a sight to see them bobbing up-and
down like wagtails. They seemed to be making south and west.'"
Vanessa cardui-The Painted Lady, was unusually scarce, only a
very few odd specimens being reported.
Vanessa atalanta-The Red Admiral. None were seen in the
spring, and in the autumn it was less common than usual, though fairly
plentiful in some places-Shiremoor and Alnmouth, for example. A great
swarm arrived at Brighton on June 5th one observer estimating their
numbers at 20,000 and another stopping his car because there were
hundreds on the road. Our own records suggest that some of these worked
northwards for the insect was