56 



THE WHITE PINE. 



A siiifTiilar fcatnn* in coiinci'tioii witli tlie iii'in)ti(m fif tliis sperios is tliat it was practically 

 Hiikiiown save in llif collections of specialists until its smldeii appearance in 1888, bnt still luon^ 

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

 had (lone a preat amount of dainajie, which has been estiniatexl at ujjwanl of a million dollars. 

 The apparent extei niination of tliis bark beetle in the district where it was most ilestructive 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 tliis i)urpose 

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

 suflicient 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 i)aint by the 

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

 also of value. A carbolated wash, which is in successful use against the i)e,ach tree borer, is i)re- 

 jjared by mixing a pint of crude carbolic acid with a gallon of soft soa]) in eight gallons of soft 



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

 not be used excei)t with the greatest caution upon young 

 trees. Whatever wash is employed should be applied to the 

 trees on the first ai)i)e<'irance of the beetles in May, and should 

 be renewed if found necessary. 



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

 ance r)f clean cultural method.;. Owners of ])ine 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 accom])Iished merely 

 by removing tlie bark of dead timber. The i)rogeny 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 l)efore the following spring. l?y pursuing this method mil- 



Fio. 6. — Tomictu eacntfrapliui : beetle, showing dor- . .ni -, ' i \ r 



.at view at left, in i.rofiie at right^.-niarged Hous of tlic lusects wdl be destroyed before they have an 



about ten times: antenna above, highly mag. opportunity to Issuc and lay their eggs for the destruction of 



(origina). Other Valuable trees. A practice known as "rossing" is in 



nse on borer-infested lumber in Canaxla. 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 <lrop 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 J>. ru/Jpoiiiis Kby., and 

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

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

 their attacks. There is, however, one exception, />. terrhrann Ol., which is usually common at all 

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

 to information received in May, l.s!»8, this or a related si)ecies is now ravaging the pine forests of 

 a portion of southern New Jersey. 



The genus Tomicus contains ])erhaps (piite as dangerous forms as tliose which have Just been 

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

 species that has been associated with the mortality of ])ines in the region about and south of the 

 District of Cohnnbia is T. incofinijihus T-ec, nr southern pine bark-beetle, which is illustrateil much 

 enlarged at lig. 0. It is reddish in color and may be reiulily sei)arated from any of the preceding 



