66 INSECTS INJURIOUS TO FOREST AND SHADE TREES. 
of yellowish white, transforming into our largest species of Grapta, and marked on 
the under side of the dull hind wings with a golden semicolon. 
The larva is an inch and aquarter long. The head is reddish black, flat in front and 
somewhat bilobed, each lobe tipped with a tubercle emitting five single black pointed 
5 spines. It is covered with many small 
white and several blackish tubercles. The 
body is cylindrical, black, thickly covered 
with streaks and dots of yellowish white; 
the second segment is without spines, but 
with a row of yellowish tubercles in their 
place; the third segment has four branch- 
ing spines, all black, with a spot of dark 
yellow at their base; and on the fourth 
segment are four spines, as there are on all 
the others, excepting the terminal, which 
has two pairs, one posterior to the other. 
The spines are yellow, with blackish branches, excepting the terminal pair, which is 
black; and there is a row of reddish ones on each side. The under surface is yellow- 
ish gray, darker on the anterior segments, with a central line of blackish, and many 
small, black dots. (Saunders.) 
The chrysalis is ash brown, with the head deeply notched ; and there are eight sil- 
very spots on the back. The chrysalis state lasts from twelve to fourteen days. 
Fic. 26. Grapta progne.—From Packard. 
16. THE SILVER-C GRAPTA. 
Grapta progne (Cramer). 
Late in June, eating the leaves, a more common spiny caterpillar than the preceding, 
being white mottled with gray, the butterfly smaller than the foregoing and marked 
with a reversed silver c or comma in the middle of the hinder wings; but one brood 
of butterflies appearing in July. 
The larva is gray, mottled with whitish; head white, with two black prickles. The 
two upper long-branched prickles upon the second ring black; no spines on the pro- 
thoracic segments; those on the succeeding rings white, tipped with black; their 
branches white, toward the forward end of the body becoming more and more tipped 
with black. (Fitch.) 
17. THE COMMA BUTTERFLY. 
Grapla comma (Harris). 
Another caterpillar closely resembling that of G. pregne, but differing in being of a 
brownish-red color in front and white or pale yellow behind. 
The half-grown larva is black, with a yellowish stripe along the side from the third 
segment to the tail, and with yellow stripes across the back, and spots of the same 
color at the base of the dorsal spines, which are yellow, tipped with black. The 
mature caterpillar is white, mottled or striped with gray or ashen, and with red 
spiracles (W. H. Edwards). It differs from the larva of G. progne in its brownish-red 
face, and in being more yellowish on the abdominal segments. 
The chrysalis is brownish-gray or white, variegated with pale brown and ornamented 
with gold on the tubercles. 
The butterfly differs from the Progne in the hind wings having a black spot on their 
center, as well as two others toward their base, and on their under sides a central sil- 
very curved mark like the letter c. Expanse of wings about two inches. It appears 
in May, and a second brood in July, August, and September. This caterpillar is more 
common on the currant and hop. 
