Geometridae 
Fig. 195 .—Paleacrita ver- 
nata. a, mature larva; b, egg, 
magnified, natural size shown in 
mass at side; c, enlarged seg¬ 
ment of larva, side view; d, 
do., viewed dorsally. (After 
Riley.) 
Canker-worm, because the great majority of the moths issue 
from the ground in the spring. It has been a great pest in 
orchards, and formerly in our East¬ 
ern cities was a nuisance, not only 
because of the injury which it inflicted 
upon the foliage of shade-trees, but 
because of the annoying manner in 
which the larvae, pendent from the 
branches by long threads of silk, were 
blown about over things and persons 
beneath them. It was to effect their de¬ 
struction that the English sparrow was 
originally imported into this country. 
The ravages of the insects upon the 
foliage of trees in parks and gardens have measurably decreased 
since this step was taken, but in the open country, especially in 
the Valley of the Mississippi, 
the insects are still numerous 
enough to do much harm 
to orchards. The females 
being apterous, the best 
method of preventing the 
multiplication of the insects 
upon trees is to prevent 
them from climbing up 
upon the foliage and ovipositing. A simple device, which has 
proved very effective, is to tie a piece of rope about the trunk 
of the tree which it is intended to protect, and to insert between 
the rope and the bark strips of tin, which, having been put into 
place, should be bent downwardly and outwardly, so as to form 
a collar with a downward flare. The insects have been found 
not to be inclined to pass such a barrier, and they will congregate 
just below it, and may there be captured and destroyed. Birds 
are the chief enemies of the canker-worm, and every wise or- 
chardist will see to it that all species of insectivorous birds are 
not molested in his neighborhood, but are encouraged to find in 
his trees a hospitable welcome. The small amount of fruit 
which the birds take as toll is amply compensated for by the 
work which they perform in keeping down insect pests, such as 
325 
Fig. 196 .—Paleacrita vernata. a, male; b , 
female; c, joint of antenna; d, joint of ab¬ 
domen; e , ovipositor. (After Riley.) 
