THE SMALL TORTOISESHELL 
149 
During the year 1933 the records of insect migration 
received by the Insect Migration Committee of the South- 
Eastern Union of Scientific Societies, refer to the appearance 
of numbers of A. urticae migrating to England. The report 
reads as follows : “ July 25th, urticae seen flying in from 
the beach. On the 26th Mr. M. B. Ellis, stationed at the 
end of Gorleston Pier between 1.30 and 7 p.m., witnessed the 
arrival of about a dozen Small Tortoiseshells among other 
insects across the sea against a slight westerly breeze. 
Aug. 2nd, 7.15 p.m., at the East Dudgeon Light Vessel, in a 
calm, a swarm of Piens brassicae and Vanessa urticae passed 
going S.S.E. Aug. 3rd, 10.30 a.m., at the Outer Dowsing Light 
Vessel, in warm, misty weather, with a light S.W. wind, 
force 2, one female Vanessa ( aglais) urticae was taken. It 
was flying S.W/' 
We are now able to account for the cause of the abundance 
of this species in some years in certain localities where it is 
often scarce, and its normal numbers being so greatly aug¬ 
mented in particular seasons. 
Time of Appearance. This species is double brooded. The 
first emergence takes place in June and July and the second 
brood butterflies emerge in August and September. Hiber¬ 
nated specimens make their reappearance usually towards 
the end of March, but these often appear on the wing during 
the winter months when the weather is sufficiently warm and 
sunny to awaken them from their winter’s sleep. Butterflies 
of the second brood sometimes remain on the wing until 
early November. 
Hibernation. Many of these butterflies enter into hiberna¬ 
tion very shortly after emerging in July and August, apparently 
remaining on the wing for a day or two only. A specimen 
which flew indoors on one of the hottest days of summer, viz. 
August 6th, 1933—when the shade temperature reached 93 0 F. — 
took up its winter quarters on the ceiling of the landing in 
my house during the afternoon and remained motionless from 
that day until March 24th of the following year, having 
been quiescent for 230 days. When it took flight, I found 
it then in perfect condition ; apparently it entered into 
hibernation almost at once after emerging in August. Another 
specimen I kept under observation settled down for hiberna- 
