Caterpillars that feed on the foliage of trees and shrubs may {15} be
obtained by beating. The collector with one hand holds an open and inverted
umbrella, or a Bignall tray made expressly for the purpose, under a branch,
whilst with the other hand, armed with a stick, he strikes the branches
from above in the direction of the receiver held below. In conducting such
operations some collectors are far too energetic. It should be remembered
that it is not hard thrashing, but a sudden jar that dislodges the
caterpillars most readily.
[Illustration: FIG. 15.