IMPORTANT PECAN INSECTS AND THEIR CONTROL. 



37 



the head end the pupa WTiggles along the tunnel to the exit hole, 

 after which the skin splits open and the moth emerges. 



CONTROL MEASURES. 



All that can he done to control this insect in pecan orchards is 

 to locate the larger limbs and tree trunks attacked, and destroy the 

 larvae by injecting small quantities of carbon disulphid into the 

 holes, which should be stopped up im- 

 mediately after treatment by means of 

 putty, grafting wax, wooden pegs, or 

 moist clay. 



THE FLAT-HEADED APPLE-TREE BORER.i 



The flat-headod apple-tree borer has 

 been laiown long as a more or less serious 

 pest of certain fruit trees, such as the 

 apple, quince, pear, peach, and apricot, 

 and among its food plants are to be in- 

 cluded several shade and forest trees. 

 Dm-ing the last few years this insect 

 has been recognized in many sections 

 of the pecan-growing bolt as a serious 

 enemy of pecan trees grown mider or- 

 chard conditions, and in imiumerable 

 cases its larvae have girdled and Idlled 

 young trees. Its injuries are for the 

 most part restricted to newly trans- 

 planted nursery trees and to trees that 

 suffer from micongenial soil or droughts, 

 or are damaged by ' ' barking ' ' with culti- 

 vating implements. Pecan trees that 

 have been affected by winter injury 

 are very susceptible to the attacks of 

 this borer. It is woU known that 

 pecan nursery stock does not stand transplanting so woU as do many 

 orchard fruit trees, as, for instance, the apple or peach, and perhaps 

 this is because so much of the taproot is cut off in removing the 

 trees from the nursery row. For the first year or two transplanted 

 pecan nureery trees make little growth and do little more than estab- 

 lish themselves, even when the planting is done at what is considered 

 the best time and with the utmost care. If the spring and summer 

 following the setting out of the young trees are deficient in ramfall, 

 the trees may be more or less seriously attacked by flat-headed 

 borers, as the beetles seem to prefer to lay their eggs upon wcakejied 

 or devitalized trees. 



Fig. 43.— The oak or hickory cossirl: Larval 

 burrow in pecan twig. Enlarged. 



1 ChTysohothrh fcmorata Fab. 



