INSECTS INJURIOUS TO THE HOP-PLANT 



281 



the under side of the hind wings (Fig. 207), while P. comma has the 

 same mark without the dot, which thus resembles a comma 

 (Fig. 208). 



The Semicolon-butterfly is common throughout the United 

 States east of the Rockies, and especially in hop-growing regions. 

 It hibernates over winter and is among the first butterflies to be 

 seen in early spring, when it is often attracted to the flowing sap 



a 



FIG. 207. The semicolon-butterfly (Polygonia interrogationis) : a, egg-chain; 

 6, larva; c, chrysalis; d, adult all natural size except a, which is 

 greatly enlarged. (After Howard, U. S. Dept. Agr.) 



of newly cut trees. The eggs are laid late in May or early in June, 

 usually upon the under surface of the leaves of elm, blackberry, 

 or nettle, either singly or in pendent columns of from two to 

 eight. They hatch in from four to eleven days and the larvae 

 grow quite rapidly. 



When full grown the larva is an inch and a quarter long. The 

 -head is reddish-black, somewhat bilobed, each lobe being tipped 

 with a tubercle bearing five single, black-pointed spines, and cov- 

 ered with many small white and several blackish tubercles. The 



