248 OHIO EXPERIMENT STATION: BULLETIN 332 



laterally with white. Extending down the middle of the back is a 

 pale yellow line. The remainder of the body color sometimes pre- 

 dominates greenish yellow, with distinct lighter lines extending 

 along the sides and back, but quite commonly, two broad red-brown 

 lines extend down the back with distinct lateral enlargements on 

 the first, third and eighth abdominal segments. When such a quan- 

 tity of red-brown coloration is found upon the dorsum, the sides 

 of the body also are generously sprinkled with dots of the same 

 coloration, giving the larva a distinct reddish cast. When the 

 larva is disturbed, a clear liquid appears as tiny drops from pores 

 situated in a line along the sides of its body, whereupon a very offen- 

 sive odor is noticed. (See Plate XXXVII, Fig. 1.) 



The adult moth is a pale ash-gray creature lacking notably 

 distinctive markings and having a wing expanse of nearly 1% 

 inches. The pupa likewise is without special characteristics and is 

 a little more than one-half inch in length.* 



Life history and habits. — The details of the life history are 

 not known perfectly for Ohio. During the seasons of 1916 and 

 1917, the larvae were extremely abundant in late September and 

 early October, but whether there had been an early summer brood 

 is not known since the attack was confined to the southern part of 

 the State and no opportunity was had for observations during the 

 early part of the season. Moths appear in the vicinity of Wash- 

 ington, D. C, in late April and early May, according to Comstock 

 (21). He also states that upon completing larval growth in the 

 fall, the caterpillars enter the ground and according to some evi- 

 dence remain in the larval stage during the greater part of the 

 winter. 



Nature of work. — The injury done by the variable oak leaf 

 caterpillar is confined to the destruction of foliage by the cater- 

 pillars, which during severe outbreaks may amount to complete 

 defoliation. The insect is sporadic and infrequent in its outbreaks, 

 but a number of cases are on record where great havoc was wrought. 

 It is generally considered a woodland rather than a shade tree pest. 



Food plants. — Packard (22) says that the following plants have 

 been recorded as hosts of the species : White, post, burr and laurel 

 oak; hawthorn, basswood, persimmon, walnut, apple, black birch 

 and Pickneya piibens. 



White oak is more severely injured than any other species in 

 Ohio, in the writer's observation", many trees in the vicinity of 

 Steece, Lawrence County, suffering at least a 50 percent foliage loss 



*For a thoroughgoing discussion the reader is referred to Packard's "Bombicine Moths," 

 Natural Academy of Sciences, Vol. VII, pp. 224-230. 



