VERMONT AGRICULTURAL REPORT. 79 



Exclusion. — This method of combatting the borers seems to the 

 writer to be the more hopeful if the work is carefully done. Various 

 materials may be used for wrapping the trunk, such as heavy wrapping 

 paper, manila paper, tar paper or fine wire screen. Their efficacy is en- 

 tirely dependent on the care and skill with which they are put on. To be 

 effective they must fit sufficiently close to the trunk and come up high 

 enough to prevent the beetle from depositing its eggs. The material 

 used in fastening the wrappers should be such as is easily broken by the 

 growth expansion of the tree. The employment of tar paper or fine 

 wire netting serves the double purpose of excluding insects and protect- 

 ing the trunks from injury by mice, rabbits or other small rodents. One 

 objection sometimes urged against wrapping the tree trunk with heavy 

 paper, is that, upon its removal, it renders the tree more subject to sun 

 scald. Another, which might be raised, is that unless examined occa- 

 sionally, the wrapper is apt to get disarranged and instead of being a 

 protection it maye serve as a screen for the insects. 



Repulsion. — The application to the tree trunk of some caustic or ill- 

 smelling compound serves to repel the borer in proportion to the 

 thoroughness with which it is used and the persistency of the retention. 

 Most of the washes employed are of an alkaline nature, consisting of 

 soaps, or lyes, caustic in their action, to which, frequently, enough 

 carbolic acid is added to give an offensive odor. Quite recently painting 

 the tree trunks with pure white lead and linseed oil has been highly 

 recommended by Alwood of the Virginia station, as being an effective 

 repellant of the round-headed apply-tree borer. The ease of application 

 and the persistency of the material should warrant its trial on a small 

 scale in this latitude. Various patent washes have been from time to time 

 widely advertised. Most of these compounds contain coal-tar pro- 

 ducts, which, while ill-smelling enough, are more or less injurious to the 

 trees. Such are not, as a rule, to be recommended. It is evident that 

 the protection of the trunk by washes can be effective only when it is 

 kept covered with it. 



Remedies. — After the larva has entered the tree, there is practically 

 but one thing to do. It must be dug out. A strong bladed knife and a 

 rather strong, flexible wire are the only tools required. It is usually 

 stated that it is sufficient to go over the trees twice yearly, in May and 

 September. The writer recommends that, in badly infested orchards, at 

 least, a further inspection be made in July. Many of the newly laid eggs 

 could then be destroyed. The presence of the young larva in the tree is 

 usually easily detected, since they lie near the surface and generally 

 cause a slight flow of sap from the wounded tissue. The bark, moreover, 

 is usually somewhat discolored. They are easily reached at this stage of 

 their development, and, if destroyed, cause but little injury to the tree. 

 As they grow older they advance deeper into the wood and their pres- 

 ence can only be detected by the fresh castings that are pushed out as 

 they gnaw through the wood tissues. The knife is used to remove the 

 castings which clog the tunnel and then the flexible wire is inserted. If 

 the course of the larva is not too devious, one can generally succeed in 



