394 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



" may be entrapped by digging a trencli either around the individual 

 tree or around a grove or belt. The trench should be at least a foot 

 deep, with the outer wall slanting under. Great numbers of worms 

 will collect in it, or bury themselves in its bottom, and may easily be 

 killed." 



22.. Hepialus argenteomaculatus Harris. 



Mr. Harrington is authority for the statement that a moth referred 

 to this species has been bred by Mr. Fletcher from a larva found boring 

 in the base of a spiked maple (Acer spicatum). (See p. 346.) 



23. The io caterpillar. 



Syperchiria io (Fabricius). 



Order Lepidoptera ; family Bombycid^. 



Sometimes feeding late in summer on the maple, a large, greenish, thick caterpillar, 

 "with fascicles of irritant, radiating, sharp spines over the body, spinning a thin 

 silken cocoon among the leaves, and transforming the following May or June into a 

 large, stout-bodied moth; the males yellow with a very large eye-like spot on the 

 hind wings, and the females purple-brown, the wings of the latter expanding nearly 

 3 inches. 



Although this large caterpillar is a general feeder, devouring in the 

 Southern States the leaves of the Indian corn, as well as the sassafras, 



black locust, the false indigo, wild 

 black cherry [Primus serotina), and 

 the willow, currant, cotton, clover, 

 elm, hop- vine, balsam-poplar, balm 

 of Gilead, dogwood, and choke 

 cherry, we have found it in Maine, 

 where it is a rare moth, feeding on 

 the rock or sugar maple, and hence 

 refer to it under this head. The 

 eggs are top-shaped, attached by 

 the smaller end, in patches of 

 about thirty, on the under side of 

 leaves. The caterpillars in the 

 Western States begin to hatch 

 about the end of June, getting 

 their growth in two mouths, after 

 molting five times. The spines are 

 poisonous to the fingers, and the 

 caterpillar can not be handled 

 without causing some pain and irritation. 



Mrs. Dimmock has summarized in Psyche (iv, 275) what is known of 

 the habits of this caterpillar as follows : 



Hyperchiria io Fabr. (Syst. Entom., 1775, p. 560). Harris (Rept. Ins. Injur. Veg., 

 1841, p. 283-285) describes the larva and male and female images ; later (Treatise on 

 Ins. Injur. Veg., 1862, p. 393-396) he adds to the descriptions figures of the larva, 



Fig. 148.— Green stinging io caterpillar. — After 

 Riley. 



