169 



less branched, and green tipped with black. These spines are sharp and 

 poisonous, and unless the larva) are handled very carefully or with 

 gloves will puncture the skin, causing white elevated blotches, some- 

 times followed by swelling, inflammation, and i)ain, continuing for days. 

 The full-grown larva is about two and a half inches long. It descends 

 to the ground and forms a rough covering in the loose leaves and 



Fig. 101. Hyperchiria io, female. Natural size. 



rub})ish, within which it spins a slight cocoon of tough, gummy silk, soon 

 changing to the pupa. 



lOxcept possibly in the extreme South, this species is single-brooded. 

 A few moths (Fig. 160, 161) emerge in fall, but most continue in the 

 pupal stage over winter, emerging in June and July. The caterpillars 

 are found with us from the middle of June to the middle of September, 

 the average larval life })eing about two months. 



THE SORGHUM WEB-WORM. 



Celama sorghiella Riley. 

 (Nola sorghiella.) 



This troublesome pest of the sorghum plant, which weljs the })rush 

 and seeds together, may be mentioned here because it has been taken 

 by Ashmead from tassels of corn. In sorghum numerous delicate tulles 

 are formed, through which the caterpillars pass, feeding primarily on the 

 germ but sometimes devouring the whole seerl. 



The mature caterpillar is half an inch long, yellowish or light greenish 

 yellow, with a small yellowish head. There is a sulphur-yellow line along 

 the middle of the back, and on each side a brownish longitudinal stripe 

 and a transverse row of six tubercles on each segment, each tubercle 

 bearing a yellow bristle tipped with brown. These caterpillars are 

 active when disturbed, and transform on the gromid in delicate 

 cocoons covered with particles of foreign material. 



