THE WALL BUTTERFLY 
47 
flight is rapid but only of short duration ; when disturbed it 
flies only for a few yards and settles again ; this it repeats 
time after time. 
Like the Speckled Wood, the Wall had disappeared from 
many places during the past 
half century. But during the 
last few years, it has put in its 
appearance again in certain 
localities ; its abundance, how¬ 
ever, varies considerably from 
one year to another. 
Whether P. megera occasion¬ 
ally migrates to or from this 
country is very doubtful, but 
according to a report sent in to 
the migration committee of the South-Eastern Union of 
Scientific Societies, is the following interesting record : “At 
Outer Dowsing Light Vessel, 30 miles east of the Humber, 
August 20th (1933), at 9.15 a.m., in a west wind, force 3, one 
Pararge megera taken flying east in good condition (J.W.R.R.).” 
Distribution. The Wall is generally distributed and com¬ 
mon over the southern half of England and Wales, becoming 
less numerous and more local in the northern counties and 
Scotland as far north as Aberdeenshire. It has also occurred 
in the Isle of Man. In Ireland it is abundant everywhere 
throughout the country. 
Time of Appearance. This butterfly is normally double- 
brooded, the first brood appearing on the wing in May and 
June, the second in August. In fine and very warm summers 
three broods generally occur, the first in April and May, the 
second in June and July, the third in September and October. 
Hibernation. This butterfly passes the winter in the larval 
state, but only undergoes partial torpidity, as it becomes 
active and feeds at times throughout the winter months when 
the temperature is mild. 
Egg and Egg Laying. The eggs are laid singly on the blades 
of grasses and hatch in about ten days, according to the 
temperature. The egg is large in proportion to the butterfly, 
consequently about fifty or sixty eggs only are laid by this 
species. It is spheroid in shape and 0.91 mm. high. The 
The Wall Butterilv 
[Female ab.). 
