324 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



Work on the relation of climate to insects and other life under the 

 new science of bioclimatics has been continued, both at Washington 

 and at a temporary field station in West Virginia. 



Principal results. — The most important result of the year is 

 one for Avhich we have been sti-iving for many years, namely, 

 increased interest and confidence in the work of the branch of forest 

 entomology and its recommendations. This is now manifested in a 

 most gratifying way by National Forest, National Park, and Indian 

 reservation officials, and especially by representatives of some of the 

 principal ]irivate owners of timber and manufacturers of -forest 

 products. There is a marked increase in requests for information 

 and advice and for our cooperation in dealing with some of the big 

 problems involving the loss of standing timber and forest products. 

 It is becoming recognized, especially in the AVest, that forest ento- 

 mology is an essential phase of forest conservation. The increased 

 interest and confidence are also shown in the fact that within the 

 closing months of the fiscal year, over 1,400,000 infested trees, rep- 

 resenting more than 8,000,000 board feet of timber, were treated 

 according to the recommendations and under the supervision of rep- 

 resentatives of this bureau, at a cost of over $46,000. 



Inspection of areas on which control work was done during re- 

 cent years showed most gratifying results in the ending of the 

 epidemics and consequent saving of a great quantity of timber. 

 Among other results that may be mentioned are : 



(1) A^erification of the principle of continuous logging operations 

 as a means of preventing epidemics of tree-killing insects. 



(2) Evidence that the epidemics of tree-killing insects do not 

 come in regular but in irregular cycles. 



(3) Demonstrations of the importance and economy of coopera- 

 tive insect-control work. 



(4) Evidence that hardwood submerged in water, as sawlogs or 

 as lumber, is immune against powder-post attack after the wood is 

 seasoned. 



(5) The discovery in practical tests that liquid orthodichloro- 

 benzene is effective in killing borers after they have entered the 

 wood, and that paradichlorobenzene dissolved in kerosene gives 

 similar results. 



(6) Practical tests of the solar-heat method of killing insects 

 in the sapwood of sawlogs and of preventing attack show that under 

 certain conditions it is both practical and effective. 



(7) The, management prhiciple of preventing losses from insect 

 depredations, as related to damage to forest products, defoliation 

 of fir and spruce by the spruce budworm, and tree-killing insects 

 in general, is becoming recognized as of fundamental importance 

 in lumbering operations and general forest conservation. 



BEE-CULTURE INVESTIGATIONS. 



The work of the bee-culture laboratory, under the supervision 

 of Dr. E. F. Phillips, has been conducted along the same general 

 lines outlined in the report of last year, namely, the emphasis of 

 investigational work rather than educational work such as was con- 

 ducted during the war. The projects under which this work is 



