THE COMMON CABBAGE WORM. ‘i 
late Dr. S. H. Scudder, who was the highest authority on American 
butterflies. The westward spread has not been followed carefully. 
FOOD HABITS. 
The imported cabbage worm feeds on all forms of cruciferous 
plants, is particularly fond of cabbage and cauliflower, and is some- 
what less destructive to turnip, kale, collards, radish, mustard, anc 
horseradish. It also does considerable damage to ornamental plants, 
such as nasturtium, mignonette, sweet alyssum, the spider plant 
(Cleome), and exceptionally to lettuce. 
The butterflies sip the nectar of flowers of various kinds and may 
be seen at any time hovering over them. They are especially fond 
of the white blossoms of crucifers, and of the flowers of white aster, 
lavender, purple heliotrope, and thistle. Like other butterflies, this 
species is active by day, and is on the wing from early morning until 
near dusk. It is a comparatively slow, tireless flyer, being capable 
of extended flight for long distances. The butterflies sometimes 
congregate in immense swarms, as has occurred frequently when 
they have emigrated from the continent of Europe to England, and 
their occurrence in midocean has been recorded. 
LIFE HISTORY. 
The butterflies appear on warm sunny days as early as March, 
even in. the Northern States, and thereafter may be seen flying 
until after several severe frosts in October. In the Gulf region they 
occur throughout the season. 
Pairing and egg laying begin within a day or two after the adult 
issues from the chrysalis. The duration of the different stages 
naturally varies with temperature conditions, that of the egg period 
being from 4 to 8 days. 
The caterpillar eats voraciously and grows rapidly, attaining 
maturity in from 10 to 14 days after hatching. It molts four times; 
hence there are five distinct instars or substages, the first molt taking 
place, in the warmest weather, in about 2 days from the time of 
hatching, the second stage lasting from 2 to 3 days, the third and 
fourth from 1 to 2 days each, and the fifth from 4 to 5 days. The 
duration of the chrysalis stage is from 7 to 12 days during the sum- 
mer time, but the last chrysalides formed in the more northern 
States remain in suspense during the winter and develop the follow- 
ing spring. 
The life cycle occupies periods varying between 22 days and 
5 to 6 weeks. Even in New England this species is credited with 
being triple brooded, but in the District of Columbia and vicinity 
