394 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION, 
'•may be entrapped by diggiug a trench 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, aud may easily be 
killed." 
22. W e pi m h u argenteomaculaiun 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. 34:6.) 
23. The io caterpillar. 
Hypercliiria 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 amoug 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 iudigo, 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 : 
Hypercliiria io Fabr. (Syst. Entoin., 1775, p. 560). Harris (Kept. Ins. Injur. Veg., 
1841, p. 283-385) d< 'scribes the larva and male and female imago*: later (Treatise on 
Ins. Injur. Veg., 186*2, p. 393-396) he adds to the descriptions figures of the larva, 
Fig. U8.— Green stinging io caterpillar.— After 
Ril.-y. 
