DESTRUCTIVE INSECTS. 



195 



soap, tallow, tansy plant, whale-oil soap, lime and linseed oil, 

 hydraulic cement wash, pine tar, and one application of Hale's 

 wash. 

 The following methods proved to be quite effective — that is, 



Fig. 260. — The Fruit-tree Bark- beetle, u^ Beetle ; ^, same in profile ; c, pupa; 

 d^ larva; all enlarged about ten times. (U. S. Div. of Entomology.) 



most of them kept out over one-half of the borers: Hale's 

 wash (two applications), mounding, tarred paper, tobacco 

 stems, digging out, and gas tar. 



In regions less moist than in Central New 

 York it is possible that some of the methods, 

 listed above as unsatisfactory, will prove 

 good preventives against this serious pest. 

 Washes should be applied about June 15th 

 in Northern orchards, and must remain in- 

 tact for over two months. 



The Fruit-tree Bark-beetle or Shot-hole Borer 

 {Scolytus rugulosus).—Th& bark of plum, 

 peach, cherry, and apple-trees may appear 

 thickly " peppered " with holes, as though by 

 fine bird shot (Fig. 261). These are the en- 

 trance and exit holes of a small beetle (Fig. 

 260 a) whose grubs (Fig. 260 d) excavate 

 narrow galleries in various directions under 

 the bark, and often kill the tree or some of 

 its branches. Usually only sickly or un- 

 thrifty trees are attacked by the insect. 



It is a very difficult insect to combat. Bad- 

 ly infested trees should be burned at once. 

 Keep the trees in good health and they will 



Fig. 261.— Work of 

 the Fruit-tree 

 Bark- beetle in 

 Twig of Apple, 

 natural size. (U. 

 S. Div. of Ento- 

 mology.) 



