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The protection of fi Pire-ki tied 1 Dowglas fir fir.--J. M. Whiteside, of 
the Portiand laboratory, reports that an attempt has been made to 
thwart the attacks of insécts in Douglas: fir recently: fatally scorched 
by fire. Using a powerful poison solution, with a dye to indicate 
its pith through the tissues, the first of a series of tree-injection 
tests have been made to. determine whether it will be possible to pro- 
téect fire-killed timber from the ravages of insects until Logging 
operations can salvage these valuable loge At. the present, time, the 
solutions have not ascended to any great height owing to the dormant. 
condition of the trees. It is srobable that the. trees.will take up 
the solutions slowly during the winter and more rapidly in the early 
spring, when it is hoped that. sufficient protection will be afforded 
to repel the attacks of insects. W. D. Bedard,:Coeur d'Alene, Idaho, 
spent several days in December at the Portland laboratory, assisting: 
ae the medication -f fire-scorched trees in an effort. to preserve the 
wood from deterioration. The same injection technique used to medi- 
cate western white pine was applied to the fire-scorched tre COS 5: and . 
but few modifications were necessary. 
Bark—beetle parasites and control.---Mr. Beda rd has recent] ly com— 
pleted a preliminary report concerning the relation of parasites and 
» the control cf the mountain pine beetle (Dendroctonus 
monticolae Hopk.) in-western white pine. This ‘renort points out 
that although artificial control can reduce the bark—beetle popula-, 
tion in a given area, the numbers of beneficial insects-are .reduced © 
Bb OE S00 Therefure, when control has been cotupleted, the 
intensity of the infestation has been reduced, but the potential of: 
future increase remains the same. If the natural enemies of. the -bark 
beetles can be preserved -during control, however, while the bark 
beetles are destroyed, it may be bosses sheen oven increased parasiti- 
zation to reduce ‘the potential’ increase of. the infestation. The ré- 
port describes criteria whereby trees containing a high percentage, of 
parasites can be recognized by men marking the trees for treatment,- 
thus enabling then to leave such trees untreated. 

oy 
Vectors of Dutch elm disease.--In connection with the work upon 
insect vectors of the Dutch elm disease, carried on by special re-—:- 
Search funds made available by E. C. W. and in cooperation with the 
New Jersey Agricultural Experiment Station, a number. of .elm:trees.are 
now in full leafage and growing as in early summer; . This condition: 
has been brought about through the cooperation of Dr: ». Denny. of. thes 
Boyce Thompson institute, Yorkers, N. Y., who by tre Bion EG with cer- 
tain gases> succeeded in the difficult task of breaking the: dormancy. 
of the trees‘in midwinter. arious beetles. considered.as probable: . 
or possible vectors of the diséase are also starting to. emerge; in 
considerable numbers from logs infested by the Dutch elm disease. 
W. D. Buchanan, conducting the laboratory work on insect.vectors, 
hopes to get earlier information as to what insects are culpable than 
