LEPIDOPTERA . 
383 
surface of the hind wings are pale lemon-yellow. In the 
female there are two spots on the outer part of the fore 
wing besides the black tip, in the male only one (Fig. 
462). There is considerable variation in the intensity of 
the black markings, and in the extent of the yellow tinge of 
the wings. 
The larva of this species (Fig. 461) feeds principally on 
cabbage, but it also attacks many other cruciferous plants. 
Its color is the green of the cabbage-leaf, with a narrow, 
greenish, lemon-yellow dorsal band, and a narrow, inter¬ 
rupted stigmatal band of the same color. The body is 
clothed with very fine short hairs. 
Pieris rapes is without doubt the most injurious to agri¬ 
culture of all our species of butterflies. It is an introduced 
species, but has spread over the greater part of this coun¬ 
try. As it is three-brooded in the North and probably 
more in the South, it is present nearly the entire season, so 
that it needs to be fought constantly. Owing to the im¬ 
practicability of using poison upon cabbage, and to the fact 
that the larva bores into the heart of the cabbage beyond 
the reach of applications to the plant, it is an exceedingly 
difficult insect to combat. Obviously it is important in 
fighting this insect to thoroughly subdue the spring and 
summer broods, so that the bulk of the fighting can be 
done before the cabbage begins to head. For this purpose 
pyrethrum and kerosene emulsion have been found most 
useful. 
The Gray-veined White, Pieris oleracea (Pi'c-ris ol-e-ra'- 
ce-a).—The wings are white above and below, with a scarcely 
perceptible tinge of greenish yellow. Sometimes there is a 
dark spot on the fore wing between veins V s and VII,, but 
usually the wings are unspotted. The base of the wings, 
however, and the basal half of the costa of the front wings, 
are powdered more or less with dark scales, and the veins of 
the wings, especially on the lower side, are grayish. 
This species occurs throughout Canada and in the more 
