INSECT PESTS OF OHIO SHADE AND FOREST TREES 329 



Food plants. — In Ohio, oaks serve as the chief host but it has 

 been reported on maple, apple, pear, plum, peach, grape, quince, 

 orange, hickory, chestnut, locust, sassafras and sumac. In addition 

 to this list, it is possible that elm should be added as well as several 

 other hosts but at the present time the records are not sufficiently 

 conclusive to warrant doing so. 



Distribution. — This insect not only is distributed throughout 

 the state but also occupies a wide range of territory throughout the 

 eastern and central sections of the United States. 



Natural enemies. — Birds are the chief natural enemies of this 

 species. The woodpeckers, of course, are of greatest value and in 

 addition the chickadee and blue jay may be mentioned. 



Control. — No method is known whereby the beetles may be 

 prevented from laying their eggs in the twigs. Something may be 

 accomplished, however, by way of controlling the species if all fallen 

 twigs be collected before the beetles emerge in the spring. In parks 

 and on lawns this practice is highly commendable, particularly if 

 no forests or woodlots are in the immediate vicinity. 



THE CARPENTER WORM 



(Prionoxijstus robiniae Peck) 



Description. — The carpenter worm is one of the largest of the 

 destructive borers, the galleries which the well-grown caterpillar 

 makes in the heartwood of the host sometimes measuring over 1 

 inch in diameter. 



The mature insect is a beautiful moth, the female measuring 

 about 3 inches across her expanded wings. The general color is 

 dark gray, mottled with a lighter shade. The hind wings show less 

 mottling and sometimes are faintly tinted with yellow. The body 

 is long, cylindrical and heavy, especially when distended with eggs. 

 (See Plate LXVII, Fig. 3.) 



The male is smaller, measuring about 2 inches across his ex- 

 panded wings. In general he resembles the female. The fore 

 wings are slightly mottled but in general are darker ; the hind wings, 

 however, are quite different due to the presence of a large yellow 

 or orange area along the outer margin. 



Doctor Felt says: "The eggs have a broadly oval form and 

 are about one-half the size of a grain of wheat, being about one- 

 tenth of an inch in length and about three-fourths of an inch in 

 diameter. They are of a dirty whitish color with one of the ends 

 black, and when highly magnified, the surface is seen to be finely 

 reticulated or marked by rows of slightly impressed dots." 



