After the caterpillar changes to a chrysalis, their minute parasites frequently bore through the outside and deposit their eggs within. These hatch before the time for the butterflies to emerge, and feeding on the contents, destroy the life of the chrysalis.
Birds and spiders are of great service in destroying these insects.
The pupæ should be collected and burned if the abdomen is flexible; but if the joints of the abdomen are stiff and cannot be easily moved, they should be left, as they contain parasites.
Several applications of poisons have been used, the best results being obtained from the use of pyrethrum as a powder blown on to the plants by a hand bellows, during the hottest part of the day, in the proportion of one part to four or five of flour.
As the eggs are laid at different times, any application, to be thoroughly tested, must be repeated several times.
THE APPLE TREE TENT CATERPILLAR.
Clisiocampa Americana (Harr.)
Large, white, silken web-like tents, Fig. 15, are noticed by the roadsides, in the early summer, on wild cherry trees, and also on fruit trees in orchards, containing numerous caterpillars of a blackish color, with fine gray hairs scattered over the body.
This well known pest has been very abundant throughout the State for several years past, and the trees in many neglected orchards have been greatly injured by it, some being entirely stripped of their leaves. The trees in these orchards and the neglected ones by the roadsides form excellent breeding places for this insect, and such as are of little of no value should be destroyed. If this were well done, and all fruit growers in any given region were to destroy all the tents on their trees, even for a single season, the work of holding them in check or destroying them in the following year would be comparatively light.
