THE PAEANDEA BOEEE AS AN OBCHABD ENEMY. 7 



Another eonirnoii place of entrance for the Parandra borer is near 

 the surf ace of the ground where injury has been done some time pre- 

 vious by the common roundheaded apple-tree borer. 1 (PL III, 

 fig. d.) Such injuries by roundheaded borers often persist as un- 

 healed wounds and are always a source of danger to the tree. If the 

 roundheaded borers are found and removed while they are yet small, 

 the wounds made by them will heal quickly and no danger from attack 

 by Parandra borers will follow. Injuries to the trunks of trees by 

 tools in the hands of careless workmen are possible places for future 

 attacks by Parandra borers and should, of course, be avoided wher- 

 ever possible. Where such injuries occur they should be cleaned of 

 torn and splintered bark and wood and the surface thoroughly 

 painted. 



Winter injuries and diseases attacking the trunk are less easily 

 preventable, but where these are present Parandra borers may be kept 

 out at least temporarily by a liberal use of paint applied to the dead 

 surfaces. Paints so used should be renewed as often as once a year, 

 and the applications may well be made in the spring or early summer. 



Whenever borers of this species gain entrance to a tree there is 

 only one practicable way of removing them, and that is to gouge or 

 chisel out all the wood through which their burrows extend. (PI. II, 

 fig. c.) The cavity should then be properly cleaned and disinfected 

 and filled with cement. Wherever the borers are present at all they 

 are likely to occur in considerable numbers, and it is their habit in 

 feeding to scatter about through the wood so much that little can be 

 accomplished by attempting to remove them with a knife and wire, 

 as is often done with some other species of fruit-tree borers. 



In chiseling out the borers preparatory to using cement, all the 

 punctured wood and all the wood soaked with water or affected by 

 decay or disease should be removed. The interior of the cavity 

 should then be sterilized by applying creosote with a brush, after 

 which it should be painted with a heavy coat of coal tar. The cavity 

 should then be filled compactly with a mortar made of one part of a 

 good grade of Portland cement and three parts of clean, sharp sand. 2 



Trees treated thoroughly in this manner will be practically safe 



again- 1 Parandra borers until new places of attack are formed. How- 



. it is less expensive and more satisfactory in every way to keep 



trees so far as possible in such a condition of soundness that the 



borers will find no place to enter. 



idida. It is in Ion to note thai Dr. F. H. Chittenden, of the V. S. 



found i on a linden tree on the grounds of the U. 8. 



xlcultureon April 27, 1909 thai had apparently entered the tree a1 a point previously 



injur- -I 



2, '"ilii fn U. 8. Department of Agriculture Yearbook for 1918, p. 103- 



I i, 191 '.. Con u e of cement In tri 



o 



