172 
LIFE-HISTORY OF THE DIAMOND-BACK MOTH. 
fashion, under the leaves (Plate VIII., Fig. 3), in the interior of 
which they form a pretty, silver-grey chrysalis (Plate VIII., Fig. 4), 
and after about twelve days the new moth bursts forth, and thus 
they appear to keep up a succession of generations all through the 
summer, and sometimes through the autumn. 
By the courtesy of Mr. Charles Whitehead, F.L.S., who placed 
at my disposal his special report to the Board of Agriculture, 
and by conversation with others, I am able to add a few more items 
of information on this subject. The earliest recorded appearance 
of the moth is about the month of May, when they lay their eggs 
upon a number of wild plants belonging to the order Cruciferae, such 
as the charlock, pennycress, hedge mustard, and a number of 
similar plants, both on the rocks and the sea-shore, and also on the 
borders of the fields. The moths seem to continue to breed up to 
August and even to September, when they spin up their woolly 
cocoons and assume the chrysalis form upon the dead leaves of the 
plants upon which they have been feeding, or else in some sheltered 
nook near, and in this-state they hibernate during the winter 
months. 
During the early part of July they increased with such 
wonderful rapidity on the Eastern Coast that many people thought 
they must have been driven in clouds across the sea from the 
Continent; but it is scarcely probable that creatures so frail could 
fly so far, and they would have perished if driven before a storm. 
Still it is very remarkable that the ravages of this insect were 
principally confined to farms within three miles of the Eastern 
Coast, and the insect is scarcely known amongst farmers over the 
rest ot the country, although it is occasionally found feeding on 
cruciferous plants in gardens in many other parts of the country by 
entomologists. About forty years ago it is said to have done con¬ 
siderable damage in the south-east of England, and also was 
reported in 1888, 1884, and 1885, but this is the first time that the 
damage has been so serious. We will now consider some of the 
remedies. 
In aftected districts the ploughing of the land would crush or 
bury the chrysalides, thus effectively freeing it. But in early spring 
August, 1893. 
