Although oft-times a somewhat slow process, and to some temperaments,
perhaps, rather tedious work, searching for larvæ is not unremunerative
when the quality of the material obtained in this way is considered. Some
kinds sit in the daytime, or feed, fully exposed, upon the upper sides of
the leaves or on the twigs of trees, shrubs, and low herbage; these are not
difficult to see. Other kinds conceal themselves under the leaves or on the
twigs hidden by the foliage, and these have to be sought for, because many
of them cling so tightly to whatever they may be upon that hardly anything
short of a fatal blow with the beating-stick will cause them to relax their
hold. Others, again, spin two or more leaves together, and in the {16}
habitation thus formed they remain throughout the day. The latter are more
easy to see than the more readily evicted contingent. All we have to do is
to stand under the branches and look upwards and outwards, when the united
leaves and the form of the caterpillar between them will be detected. Some,
of course, will be high up and out of reach in the ordinary way, but there
will be others more accessible. Then, at night, especially in the early
spring, we may search, aided by the beam of an acetyline lamp, the plants
and undergrowth in wood rides and clearings, borders of woods, and lanes,
for caterpillars that are arousing from hibernation. Throughout all
searching operations for larvæ the chance finding of eggs under leaves or
on twigs or buds is always probable. Cocoons in addition, among the leaves
of trees and on stems of low plants and the trunks of trees, may also be
revealed.
[Illustration: FIG. 16.