INSECTS AFFECTING PARK AND WOODLAND TREE^ 



545 



controlled by thorough spraying with an arsenical poison. The larva is 

 more or less variable in coloration. It has been described as follows by 

 Professor Fernaldr The full grown larvae " are about an inch and a half 

 long, pale yellow, variegated with brown, with a yellowish line on each side 

 of the body. The head is rust-red, with two blackish, branched spines at 

 the top. The spines of the body are arranged in seven rows, one along the 

 middle of the back, from the fourth to the iith segment inclusive and three 

 rows on each side." 



This insect, as do some of its allies, hibernates in the adult and under 

 favorable conditions produces two generations. The butterflies of the first 

 brood appear early in May and disappear by the middle of June. The 

 larvae attain their growth rapidly and appear as butterflies in July, continu- 

 ing on the wing till nearly the middle of August, depositing eggs late in 

 July and during August, which produce butterflies again toward the end of 

 August. Mr Scudder states that there are at least three broods in the 

 South, and Mr Edwards thinks that there may be four or five in Florida. 



Hop merchant 



Polygonia comma Harr. 



A yellowish, spiny, black-marked caterpillar about an inch long, feeds on elm. 



This species closely resembles the preceding and according to Dr Pack- 

 ard, the larva differs in being brownish red anteriorly and white or pale 

 yellow behind. It has been described by Professor Fernald as follows : 



The mature larva is one inch long, armed with seven rows of long, 

 tapering spines ; one along the middle of the back, from the third to the 

 twelfth segment, inclusive, and three along each side ; the upper row on 

 each side running from the third to the twelfth segment ; the next row from 

 the third to the thirteenth, but the spine on the fourth is below the row and 

 in line with the spiracle ; the lower row extends from the fifth to the twelfth 

 segment. A little below the summit of each spine, from three to five 

 branches start out, each branch and spine ending in a bristle. The color 

 varies greatly ; some are black with yellow bases to the spines and a yellow 

 lateral line ; others are nearly white, with red spots along the sides. 



Its life history and habits are very similar to the two preceding, and 



