146 
damage. Heads that are so badly infested that they are past recovery 
should be burned, as by that means all the insects that might be in 
them in the different stages of development as well as the eggs would 
be destroyed. 
In addition to the above methods of attacking the insects in the 
worm and chrysalid state, the butterflies that are seen flying over the 
cabbages may be caught, thereby preventing the eggs being laid on 
the plants. For this purpose a net may be used made of musquito 
bar or other light material, fastened to a hoop of light wire attached 
to a stick about three feet long, for a handle. To be convenient to 
handle, the hoop should be about ten inches in diameter, and the wire 
not any heavier than is necessary to give it that degree of stiffness to 
keep its shape. The depth of the net should be twice the diameter of 
the hoop. 
As with other insects, man is not obliged to do all the fighting in this 
case; some species of birds, it is said, devour the larvae, and also the 
perfect insect; but the most effective foe to this species is a small 
Chalcis Fly (Pteromalus puparum) that seems to follow close in the 
wake of its host. It had been supposed that this valuable little para¬ 
site was only a native of Europe, and had been introduced into this 
country at about the same time as the Rape butterfly, but Packard is 
of the opinion that it is a native of this country, and preys also upon 
the other species of Pieris. The chrysalids of the butterfly that were 
infested by this parasite could easily be told by the livid and other¬ 
wise discolored and diseased appearance. In destroying chrysalids, 
such should not be destroyed, as by allowing them to remain, the para¬ 
sites instead of butterflies will hatch from them, and then serve as 
so much additional help toward the destruction of the cabbage 
worms. 
Besides this, one or more species of flies have been mentioned as 
parasitic to this species. 
Spec. Char. Butterfly —Expanse of wings about 1.75 inches. Male — 
Ground color of both wings above white. The tip of the fore wings and 
a round spot near the middle black. The hind wings have a dash of the 
same color on the costa a little beyond the middle. Both wings dusky 
at base. Underside fore wings white, with black spots, the second near 
the hind angle, and the tip lemon yellow, the same color reaching a 
little on the costa toward the body. Hind wings uniform lemon yel¬ 
low. Both wings sprinkled somewhat near the base with gray scales. 
There is a variety of the male that has the same markings, but the 
ground color above is lemon yellow. 
Female —Differs from the male as follows : The color above is a light 
ochre yellow instead of white. The marks are the same, except a 
second black dot near the hind angle of the fore wings; underside, the 
lemon yellow on both wings is more intense, and extends along the 
costa and outer margin of the fore wings. The body is black above in 
both sexes but light beneath. 
