;,i; THE WHITE I'INE. 



A singular feature in connection with the irruption of this species is that it was practically 

 unknown save in the collections of specialists until its sudden appearance in 1888, but still more 

 remarkable is its unaccountable, but almost entire, disappearance in 1893, not, however, before it 

 had done a great amount of damage, which has been estimated at upward of a million dollars. 

 The apparent extermination of this bark-beetle in the district where it was most destructive is 

 believed to have been due to a fungoid disease. 



REMEDIES. 



After boring insects of this class once gain access to a tree it is practically impossible to eject 

 them, and to save the tree recourse must be had to preventive measures. For this purpose 

 various protective washes are in use. One of these consists of lime, to which has been added a 

 sufficient quantity of Paris green to give it a slight green color and enough glue to cause it to be 

 adhesive. Another wash consists of soft soap reduced to the consistency of a thick paint by the 

 addition of washing soda in water. A thick wash of soap, plaster of Paris, and Paris green is 

 also of value. A carbolated wash, which is in successful use against the peach-tree borer, is pre- 

 pared by mixing a pint of crude carbolic acid with a gallon of soft soap in eight gallons of soft 



water. Fish or train oil is valuable as a deterrent, but should 

 not be used except with the greatest caution upon young 

 trees. Whatever wash is employed should be applied to the 

 trees on the first appearance of the beetles in May, and should 

 be renewed if found necessary. 



Better than any other measure, however, is the observ- 

 ance of clean cultural methods. Owners of pine forests or 

 groves will do well to cut down all dead and trim all injured 

 trees. For the protection of pines, dead spruces and other 

 coniferous trees, and such as are infested and too much weak- 

 ened to recuperate, should be cut down and destroyed by 

 burning. A great deal of good can be accomplished merely 

 by removing the bark of dead timber. The progeny of the 

 insects that have deposited their eggs in one season so 

 loosen the bark that it is an easy matter to remove and burn 

 it before the following spring. By pursuing this method mil- 



Fio. 6. Tnmicut cacoyraphut : beetle, showing dor- .-,, , 



sal view at left, in profile t rights-enlarged lions of the insects will be destroyed before they have an 

 about fc-n times; antenna above, highly mag- opportunity to issue and lay their eggs for the destruction of 



ni tit-. 1 (original). 111 *_ i ..... 



other valuable trees. A practice known as "rossing' is in 



use on borer-infested lumber in Canada. It consists in cutting a strip of bark along the full 

 length of the upper side of a log, which causes the bark to dry up and eventually drop away. 



OTHER INJURIOUS BARK-BEETLES. 



Of the other species of Dendroctonus, one has recently been reported as ravaging the spruce 

 forests of New Hampshire. It is the species at present known as D. rufipennis Kby., and 

 although not known to affect White Pine, it is not impossible that it might attack this tree in case 

 it extends its present depredations. The species of Dendroctouus are peculiarly periodical in 

 their attacks. There is, however, one exception, J). terebrans Ol., which is usually common at all 

 times over a very wide area of the United States and Canada, infesting all the pines. According 

 to information received in May, 1898, this or a related species is now ravaging' the pine forests of 

 a portion of southern New Jersey. 



The genus Tomicus contains perhaps quite as dangerous forms as those which have just been 

 mentioned. The appearance of the beetles is somewhat similar, as is also their method of life. A 

 species that has been associated with the mortality of pines in the region about and south of the 

 District of Columbia is '/'. i-uctii/ruphus'Lec., or southern pine bark-beetle, which is illustrated much 

 enlarged at fig. G. It is reddish in color and may be readily separated from any of the preceding 



