150 MOTHS AND BUTTERFLIES. 
the stems and listening for the snapping noise made by the jaws of 
the larva as it swings its head from side to side in a menacing man- 
ner. It is quite harmless, however. The pupa is interesting from its 
tongue case, which looks not unlike the handle of a jug. It is fre- 
quently found while spading or ploughing the garden. The pupa 
passes the winter several inches under ground, and works its way to 
the surface in spring when it is about to break the pupa case and 
emerge a perfect fly. (See figure on page 140.) 
This insect is widely distributed over the whole of the United 
States and Canada. 
Macrosila carolina, 
The Carolina sphinx, Macrosila carolina, very closely resembles the 
foregoing in all three stages of its existence, and also feeds on the 
same plants. It is, however, a somewhat smaller insect, and the moth 
is more brownish in color with less gray, while the black markings on 
the lower wings run more together and are not zigzag as in guinque- 
maculatus. The larva is green, stippled with white dots, with seven 
oblique whitish stripes, and a light longitudinal line extending along 
each side. The stout caudal horn is usually bluish. 
They are frequently, among the country folks, considered ven- 
omous, the caudal horn probably giving rise to the idea that they can 
sting. 
A large caterpillar, which feeds on the leaves of the elm and is 
