818 60. 
j 
ENT ed States Department of Agriculture. 
BUREAU OF ENTOMOLOGY. 
L. O. HOWARD, Entomologist. 
THE IMPORTED CABBAGE WORM. 
(Pontia rapex Jinn.) 
By F. H. Cuirrenpen, 
In Charge of Breeding Experiments. 
GENERAL CHARACTERISTICS. 
The worst of the many destructive enemies of cabbage and other cru- 
cifers is the larva or caterpillar of a white butterfly known to science as 
Pontia (Preris) rape Linn. The caterpillar, called the imported cab- 
bage worm, is altogether 
too well known by farm- 
ers throughout this coun- 
try as well as in the Old 
World, and the adult in- 
sect, the imported cab- 
bage butterfly, called also 
the white or rape butter- 
fly, is a familiar object to 
nearly everyone. It is 
generally recognized that 
the butterfly is the par- 
ent of the ‘““worms.”’ 
This cabbage worm is 
velvety green in color, 
much like the cabbage 
on which it feeds; and 
the surface of the body, 
if viewed through an or- 
: ; - Fic. 1.—Pontiarapx: a, female butterfly; 6, above, egg as 
cinairy Gandtlens;is’'seenm 6.3 som above: below. sae nateeah feonieaidge | lasers 
to be somewhat rough natural position on cabbage leaf; d, suspended chrysalis— 
paemeclmmunteda with: 2 eee 7 more Sulezeed CoxiginaD): 
small black spots. There is a faint yellow stripe down the middle of 
the back and a row of yellow spots along each side in line with the 
spiracles or breathing pores. It measures, when full grown, about an 
inch and a fourth, presenting the appearance shown in figure 1, ¢c. 
The butterfly has a wing expanse of nearly two inches, and is white, 
marked with black near the tips of the fore wings, as shown at figure 
1, a, representing the female. In this sex there are two conspicuous 
black spots on each fore-wing; the male (fig.2) has only one. Both 
32630—No. 60—06 
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