220 INSECTS INJURIOUS TO VEGETATION. 



in some rust-red, in others marbled with light and dark brown, 

 glossed with reddish white, and with a pale gold-colored semi- 

 colon on the middle of the hinder pair. Expands from 2| to 2| 

 inches, or more. 



The paly gold character beneath the hind-wings has much more 

 nearly the shape of a semicolon than of a note of interrogation ; for 

 which reason I have called this the semicolon butterfly, instead of 

 translating the specific name. It first appears in May, and again 

 in August and September, and is frequently seen on the wing, in 

 warm and sunny places, till the middle of October. The cater- 

 pillars live on the American elm and lim6 trees, and also on the 

 hop-vine, and on the latter they sometimes abound to such a de- 

 gree as totally to destroy the produce of the plant. In the latter 

 part of August the hop-vine caterpillars come to their full growth, 

 and suspend themselves beneath the leaves and stems of the plant, 

 and change to chrysalids. This fact affords a favorable opportunity 

 for destroying the insects in this their stationary and helpless stage, 

 at some loss, however, of the produce of the vines, which, when 

 the insects have become chrysalids, should be cut down, stripped 

 of the fruit that is sufficiently ripened, and then burnt. There is 

 probably an early brood of caterpillars in June or July, but I 

 have not seen any on the hop-vine before August, the former are 

 therefore confined to the elm and other plants in all probability. 

 The caterpillar is brownish, variegated with pale yellow, or pale 

 yellow variegated with brown, with a yellowish line on each side 

 of the body ; the head is rust-red, with two blackish branched 

 spines on the top ; and the spines of the body are pale yellow or 

 brownish and tipped with black. The chrysalis is ashen brown, 

 with the head deeply notched, and surmounted by two conical 

 ears, a long and thin nose-like prominence on the thorax, and eight 

 silvery spots on the back. The chrysalis state usually lasts from 

 eleven to fourteen days ; but the later broods are more tardy in 

 their transformations, the butterfly sometimes not appearing in less 

 than twenty-six days after the change to the chrysalis. Great 

 numbers of the chrysalids are annually destroyed by little maggots 

 within them, which, in due time, are transformed to tiny four- 

 winged flies {Pteromalus Vanessce), which make their escape by 

 eating little holes through 'the sides of the chrysalis. They are 



