FRUIT-TREE BARK BEETLE. 201 



squeezed out of the tobacco, and mixed with half a pailful of 

 bullock's blood, one part of slaked lime, and sixteen parts of 

 cow-dung. This is kept in an open tub, and stirred once a 

 day, and used after fermentation has set in. The rough 

 bark-moss, &c., is trimmed off the tree, and the latter painted 

 with the mixture for three successive days, until a crust is 

 formed which the rain will not wash off." The very dis- 

 gusting application may possibly act in some degree by the 

 smell of the putrefying animal matter so entirely overcoming 

 the vegetable odour, that the beetles cease to be attracted to 

 their regular host-plants. 



Two other kinds of dressings, — one known in Germany as 

 " raupenleim," the other the application known in America 

 as " dendroline," — have been suggested as possibly useful, 

 both as keeping out external attack, and preventing escape of 

 what may be within. 



Both of these materials are stated to be crude petroleum 

 products, of the nature of an impure vaseline, of a greasy 

 consistency at ordinary temperatures, and absolutely resisting 

 wash by rains. 



The "raupenleim" is stated to harden into a crust after a 

 time, and the " dendroline " to have a tendency to become 

 absorbed ; also it is said that no insect will rest upon these 

 materials long enough to lay an egg, and that no larva can 

 bore through a coating of them to reach the trunk of the 

 tree.* 



Should these "preventives" be introduced into this country, 

 they might prove of great service against Winter Moth attack 

 if applied similarly to "sticky banding" and with similar 

 care, especially in the case of " dendroline," to avoid risk of 

 the application soaking into tender bark. 



But with regard to remedial measures for the Scolytus 

 attack under consideration, probably the fairly effective plan 

 of clearing and burning infested trees or parts of trees will be 

 the method generally preferred. 



* For details and cautions in use of these preparations, more especially of 

 the dendroline, see 'Economic Entomology,' by Dr. John B. Smith, p. -iSl. 

 Philadelphia : J. B. Lippincott Company. 



