202 FRUIT INSECTS 



The Twig-girdler 

 Oncideres dngulata Say 



Twigs and branches less than half an inch in diameter on 

 many kinds of forest and shade trees and on several of the 

 orchard fruits are often neatly girdled by a handsome, robust, 

 ash-sprinkled, reddish-brown beetle a little more than half 

 an inch in length with antennae longer than its body and a 

 broad, ashy-colored belt around the middle of the wing-covers 

 and across the thorax ; closer inspection also reveals numerous 



Fig. 191. — The twig-girdler. 



light brown spots on the wing-covers. The beetles appear 

 during July and August and the girdling is done by the females 

 standing on the twig head downwards and cutting the girdle 

 section by section about an eighth of an inch wide and extending 

 to the heartwood, so that the branch is easily broken off by 

 high winds (Fig. 191). During the girdling process, which 

 often occupies half a day, the female stops several times to 

 move outward on the twig and tuck an egg underneath the 

 bark at the base of a side shoot or an aborted bud. The girdled 

 twigs are soon broken off and fall to the ground, where most of 

 the eggs hatch by autumn. In the spring the grubs bore into 

 the solid wood and often make a channel 2 inches long and 

 disposing of nearly all the woody portion of the twig, but always 



