and life cycle—Imported cabbageworm
Adult cabbage butterflies lay eggs singly on leaves. Eggs
are pale yellow to orange and are shaped like a football
standing on its end. Older larvae may be up to an inch long.
Compared with other caterpillars,
cabbageworms move slowly and are sluggish but they feed voraciously
on both the outer and inner leaves, often feeding along
the midrib, at the base of the wrapper leaves, or boring
into the heads of cabbage.
After 2 to 3 weeks of feeding, larvae pupate attached by
a few strands of silk to stems or other nearby objects. Pupae
are green with faint yellow lines down the back and sides;
there is no spun cocoon. The
cabbageworm is active throughout the year in California.