PAPILIONID^E. 
323 
The genus Pieris contains a large number of white butterflies of 
medium size, many of which are adorned with spots or markings of 
dark brown. Beneath, they are frequently yellowish white in color. 
The caterpillars are generally green, and feed on cruciferous plants, 
some of the species doing considerable damage. 
The chrysalis is somewhat angular, usually light in color, and 
although naked and fragile, and usually exposed to every breeze 
that blows, it is capable of withstanding the severe frosts and storms 
of winter, and rides safely anchored by its silken threads. The in¬ 
sects inhabit chiefly the northern hemisphere of both the old and the 
new world. 
Our most abundant species is Pieris rapce. This insect is a 
European importation which has driven our native white Pieris 
oleracea almost out of existence. It is one of the most plentiful of 
butterflies, making its appearance early in the spring, and being two 
or even three-brooded in some localities. It has a wide distribution 
over our country and Europe. The larva of this butterfly is a great 
enemy to the market gardener and farmer, sometimes devouring his 
young cabbages and cauliflowers to such an extent that nothing but 
the bare stalks remain standing in the field. 
The larva is green and covered with short down or fine hairs. 
The chrysalis is grayish or sometimes light green. This insect has 
gradually spread over the entire continent, and may be seen flying 
in swarms over fields of cabbages or turnips anywhere from Maine 
to Texas, New York to California, and no field of cruciferous plants 
is safe from its attacks. 
The heads of the cabbages are often riddled and rendered worth¬ 
less by the holes made by the larvae, and to destroy them is not an 
easy matter. Catching the butterflies with a net when first they 
make their appearance and before they can lay their eggs on the 
young plants, is perhaps the best method of keeping their numbers 
down. The vigorous use of the net for an hour a day for two or 
three days at the right time, will so reduce the numbers of this 
pest that the plants will get a good start. This is preferable to 
using emulsions of any sort to kill the caterpillars, as they are apt to 
make the plants unfit for food, a matter of considerable importance 
to the agriculturist. 
Pieris oleracea , a butterffy which not long ago was plentiful over 
a large part of the north-eastern United States, presumably owing to 
the introduction of Pieris rapce , has now become very scarce except 
