254 OHIO EXPERIMENT STATION: BULLETIN 332 



the body gradually increases in size until the hump at the rear is 

 reached and is devoid of all hairy covering. The full-grown larva 

 measures from 1% to 2 inches in length. , 



The pupa is moderately stout and blunt and measures about 

 an inch in length. The adult moth measures about 2 inches from 

 tip to tip of its expanded wings. It is light, ashy gray in color with 

 a long white area near the front margin of the front wing. 



The pale green, shiny eggs are laid in masses on the underside 

 of the leaves. 



Life history and habits. In June the moths emerge from the 

 over-wintering pupae and deposit their eggs in the masses and posi- 

 tion previously indicated. Upon hatching the larvae feed at first 

 in phalanx or at least gregariously but soon they separate and 

 spread over the tree. They reach maturity in late September or 

 early October, migrate to the forest floor and spin their silken 

 cocoons among the leaves near or on the surface of the soil. It 

 follows, therefore, that there is but one brood per season in Ohio. 

 The larvae appear most prominently in late August and September. 

 In the southern states there are said to be two broods per season. 



Nature of work. This is for the most part a forest or woodlot 

 species which damages the host by chewing away the leaves. Since 

 the caterpillar appears rather late and thus destroys the leaves 

 after they have served their greatest usefulness to the tree, its 

 damage is not so severe as if it appeared earlier in the season. 

 Moreover, this insect has never done excessively severe damage in 

 Ohio and may be considered one of the relatively unimportant shade 

 and forest pests of the state. 



Food plants. The writer has observed the pest on white oak 

 only, but other species of oak have been reported as injured, as have 

 also beech and maple. 



Distribution. Other writers give the range of this pest from 

 southeastern Canada south, and southwest to Georgia and Texas and 

 as far westward as Kansas. The eastern United States, however, 

 is perhaps the range of its greatest abundance, although in 1891 a 

 very severe outbreak occurred in Michigan. 



Control. Should this species become sufficiently abundant to 

 demand treatment, doubtless spraying with arsenicals would be 

 effective. 



THE RED-HUMPED APPLE WORM 



(Schizura concinna Sm. & Abb.) 



The red-humped apple worm, as its name indicates, is more 

 commonly a fruit tree pest than a shade and forest insect. It is 



