I08 MAINE AGRICULTURAL EXPERIMENT STATION. 



A. Insects Affecting The Trunk and Branches. 

 THE round-headed APPLE TREE BORER. Sapevda Candida, Fabr. 



The round-headed borer was first recorded in 1824 by 

 Thomas Say, but was doubtless a native of America, widely 

 distributed at that time, though unnoticed. While it prefers the 

 apple, it also affects the native crab apple, sugar pear, thorn 

 bush, pear, quince, and roundwood. 



Description. 



Eggs. — Minute, yellowish white. 



Larva. — When full grown about one inch long; footless, yellowish 

 white. Head small, chestnut brown, polished, hornHke; jaws two, black; 

 the second joint large and broad, the next two narrow. Rings of the 

 body (segments), from the fourth to the tenth inclusive, armed on the 

 upper side with two fleshy warts. 



Pupa. — Lighter colored than the larva and with transverse rows of 

 minute spines on the back. 



Perfect Insect. — A beetle, about three-fourths of an inch long, with 

 two broad white stripes extending from the head to the ends of the wing 

 cases ; cinnamon brown above ; hoary white below ; legs, antenna and 

 face whitish. 



Life History. 

 The eggs, according to Mr. Chas. Pope, who has gathered 

 hundreds of them, are laid in a short slit, made by the beetle 

 with the ovipositor, in the smooth bark. Sometimes the 

 eggs are laid in the bottom of the slit next to the wood, but 

 generally in an opening made in one side of the slit, half way 

 through the bark. Several eggs, sometimes ten or a dozen, are 

 laid on the same tree, being distributed around the trunk usually 

 within six inches of the ground, but occasionally higher and 

 sometimes at the base of the limbs. They are deposited from 

 June to September, in Maine. The egg soon hatches and the 

 young larva gnaws its way into the inner bark and sap wood. 

 When winter comes the young.borer works its way, in the wood, 

 below the surface of the soil. In the spring it ascends and passes 

 the second summer in the sap wood. It spends the second winter 

 below the surface of the soil, as it did the first. The third summer 

 it ascends and bores deep channels in the wood in every direction 

 and finally bores upward and outward, nearly to the bark, lines 

 the cavity with borings and transforms to the pupa. The third 



