COLEOPTERA. 449 
years, changing its skin many times during the period. Towards 
the end of the third year it changes into a pupa, after having 
surrounded itself with a cocoon consolidated with a glutinous 
froth and some threads of silk. The pupa (Fig. 433) is of a pale 
russety yellow, with two little points at the extremity of its body; 
the elytra and the wings, lying down, cover the legs and the 
antenne. 
Towards the end of October the perfect insect is already marked 
out, but it is still soft and weak. It passes the winter in its 
hiding-place, hardens and becomes coloured at the end of the 
winter, and shows itself by degrees on the surface of the ground. 
In the month of April, three years after its birth, the cockchafer 
emerges from the earth, and commences its attacks on the leaves 
of trees. This long duration of the development of the insect 
explains why we do not see them every year in the same number. 
When they have once appeared in great quantities, it is not for 
three years afterwards that we need expect to see their progeny 
again in proportionate numbers. It is then every three years 
that we have a cockchafer year, like 1865, but in the intermediate 
years they are never very abundant. For the first year the little 
larvee do not eat much. ‘They feed then principally on fragments 
of dung, and on vegetable detritus, and keep together in families. 
In winter they bury themselves deeply, so as to be secure against 
frost and floods. Next spring the want of a greater abundance 
of food forces them to disperse. They then make subterranean 
galleries in all directions, without, however, going far from the 
place where they were hatched. They begin attacking the roots 
which they find within their reach ; the damage they do increasing 
with their size and the strength of their mandibles. Among 
roots, they seem to prefer those of the strawberry and of rose 
trees ; but they do not despise other vegetables, and attack legumes 
and cereals as well as bushes and plants. The ravages which they 
occasion are sometimes incalculable ; market gardens are sometimes 
entirely devastated. Fields of lucerne have been seen partially 
destroyed by them, meadows of great extent lose their pasturage, 
oat fields die off before they have come to maturity, and many of 
the ears of corn fall before they are cut. 
In proportion as they increase in age and in strength, especially 
GG 
