236 INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



Nature of Work. — The bases of young trees are often almost 

 entirely girdled by the burrows of the larvas. Nursery stock should 

 be closely inspected for such injuries. Older trees are usually 

 attacked only where wounds, sunburns or dead portions occur. From 

 these areas, however, the larvae often push their burrows into per- 

 feetly healthy tissues. Diseolorations of the bark above the burrows 

 indicate infestation. 



Distribution. — This is a very common pest throughout the entire 

 State and country. 



Food Plants.— Many plants are attacked by this beetle, including 

 apple, apricot, ash, mountain ash, beech, box-elder, cherry, chestnut, 

 currant, hickory, horse-chestnut, linden, maple, oak, peach, pear, 

 pecan, plum, prune, raspberry, rose, sycamore and willow. Oak is 

 apparently the normal food plant. 



Control. — The first precaution is to thoroughly inspect all nursery 

 stock and see that no infested trees are planted. Trees should also 

 be protected from sunburn and cultivator wounds. A fairly good 

 wash to prevent the attacks on healthy trees is a solution of soft 

 soap, reduced to the consistency of paint, to which is added a strong 

 solution of washing soda. To every 10 or 15 gallons of this mixture 

 add 1 pint of 25 per cent crude carbolic acid. This should be applied 

 in the same way as paint in May or June, and again in July or 

 August. Whitewash applied in the same manner has also proven to 

 be a very good repellent. The larva? may be dug out with a knife 

 blade or killed with a crooked wire in their tunnels during the late 

 fall of the year. 



Natural Enemies. — In some localities natural enemies play quite 

 an important role in the subjugation of this pest. The following 

 hymenopterous parasites have been reared from the larva 1 : Bracon 

 charus Riley, C rypt us grallator Say and Labour apical is Cr. 137 Wood- 

 peckers also destroy considerable numbers of them. 



THE WESTERN TWIG-BORER 



Apate punctipennis (Leeonte) (Family Bostrychidse) 

 (A.mphicerus punctipennis Leeonte) 



(Figs. 225, 226) 



Description. — The beetles are dark brown with feet and other por- 

 tions of the body clothed with fine yellowish-brown hair. The length 

 is aboul \ inch and the width T : V inch. The head is held at right angles 

 to and directly beneath the prothorax. The front of the prothorax is 

 covered with distinct spine-like projections which easily distinguish 

 this species from other common twig-borers. The wing covers are 

 coarsely punctured and appear very rough. This species is larger 

 than the Eastern apple twig-borer, Apate (Amphicerus) bicaudatusS&y. 



Life History.— All that is known of the life history is that the 

 beetles breed in trees and reach maturity in the spring of the year, 

 when they often become quite numerous. 



Nature of Work. — in the case of orchard trees, burrows are made 

 into the growing twigs, .is shown in Fig. 226. The burrows usually 



'"Insi cl Life, III. p. 464, L89Q, 



