he 
work of insects and decay is crumbling. many from the tops downward, 
but a large number of them will undoubtedly remain standing for 
many more years—a serious fire menace to the associated young growth. 
This area was examined during the study on OS Ee et ee of fire- 
killed Does se fir. 
Experiments in injection of fire-killed Douglas fir. With the 
idea of lengthening the life of the fire-killed Douglas fir on the 
Tillamook burn, an interesting set of experiments were conducted dur- 
ing the past 4 months by J. M. Whiteside of the Portland, Oreg., field 
laboratory, and have recently been completed. Using a strong solu- 
tion of mercuric chloride to preserve the wood from the deterioration 
wrought by wood-boring insects and fungi, five series of tests, using 
23 Douglas firs varying in condition from green and healthy to those 
badly burned in the history-making forest fire of August 1933, have 
been made. In spite of the fact that the rise of sap and opening of 
the buds of Douglas fir occurred a month early, fullowing an extremely 
mild winter which established new climatological records for this 
section, the trees did not readily absorb the preserving ‘solution. 
The height reached in the green check trees was very small, compared 
With the total height of the trees, and almost negligible in the 
burned trees. Had these tests been made shortly after the burning of 
these trees and during a period of low humidity and high-temperature, 
better results might have been obtained. 
Caging experiments summarized.--A progress re ,ort by We. J. Buck- 
horn, of the Portland, Oreg., field laboratory, on the Ochoco caging 
experiments conducted last season, has been completed during the 
month and is now being ty,ed. A compilaticn of the deta brought to 
light many little known and interesting habits of some of the common 
insects inhabiting ponderosa pine, besides giving important data on 
the seasonal history of the western pine beetle. . 
For instance, the different insects show a marked difference in 
their periods of emergence. Most of the s»ecies emerged in early 
summer but some did not emerge until late in the season. MTrypodendron 
ponderosae Sw. was one of this type with 94 percent of the emergence 
eccurring between October and December 7. Many species emerged during 
warm days in the middle of winter. The most prominent of these was 
Rhizophagus sculpturatus Mann. and Ios emarginatus (Lec.). More than 
one adult of Dendroctonus brevicomis L Lec. may use the same exit hole 
upon emerging, and in one instance 53 percent more beetles energed 
than there were exit holes. 
