INSECTS AFFECTING PARK AND WOODLAND TREES 519 



segment toward the extremities, is light apple-green, granulated with white 

 and with seven oblique stripes on each side, formed by the whitish granula- 

 tions which are more numerous there than elsewhere. The caudal horn 

 is r / s inch long, brownish, and covered with black spinules. The head is 

 quite pointed and bifid at the top. 



Red-humped oak caterpillar 



Symmerista albzfrons Abb. & Sm. 

 A red-headed, striped caterpillar with a conspicuous red hump on the eighth 

 abdominal segment, feeds on oak in midsummer. 



This is a rather common species on oak, and in its early stages at 

 least, is easily recognized by its very large, swollen red head in conjunction 

 with the conspicuous reddish enlargement on the eighth abdominal seg- 

 ment. Ordinarily these caterpillars are not very abundant, though there 

 are records of considerable areas being defoliated by voracious hosts 

 belonging to this species. Dr James Fletcher records serious injury to both 

 oaks and maples at Ottawa Can. in 1884. 



Description. The larva has a large, orange-red, swollen head distinctly 

 raised .toward the apex. It is wider than the thoracic segments and the 

 body increases gradually in width back to the red enlargement of the 

 eighth abdominal segment. The body is smooth, shining, with no hairs 

 and ornamented with a pair of subdorsal yellow lines inclosing five median 

 black lines on a pale lilac ground. There are three black lines below the 

 yellow line and a second yellow line below the spiracles. Anal legs pale 

 orange-red, true legs pale orange. Length when full grown about 

 inches. 



The moth has a wing expanse of about 2^ inches and is easily recog- 

 nized by its whitish ash color, the square apex of the fore wings and the 

 broad white costal margin on the outer two thirds of the same. 



Life history. The pale green, subglobose eggs are laid in small masses 

 on the underside of the leaves, and the young caterpillars, at first grega- 

 rious, scatter over the tree after the first or second molt. The larvae are 

 common on white oaks in August and through September, attaining full 



