244 ANNUAL BEPORTS OF DEPARTMENT OP AGRICULTURE. 



vestigations have been made of all remedies proposed against the 

 louse. Especial researches have also been undertakem in the search 

 for new lines of treatment. Results of all tests are immediately 

 communicated to the office of the Surgeon General of the War De- 

 partment. 



The chief of the bureau has been made chairman of the subsection 

 of medical entomology of the National Research Council, and in this 

 way all questions that arise are officially handled. 



The work on insects affecting domestic animals, as outlined in the 

 last annual report, has been continued. The insects frequenting 

 packing houses and abattoirs have been under observation. Traps 

 of different kinds have been experimented with, and the other lines 

 of work indicated in the last annual report have been followed up. 



INVESTIGATIONS OF INSECTS AFFECTING FOREST RESOURCES. 



The work of the branch of Forest Insects, under the supervision 

 of Dr. A. D. Hopkins, has been concentrated during the year on sub- 

 jects which have a direct or indirect bearing on war-time needs. 



Early in the year a conference was held with representatives of 

 the branches of the War and Navy Departments, Shipping Board, 

 etc., who are responsible for the supplies drawn from the forest 

 resources of the country. The object of this conference was to offer 

 the services of the bureau and explain how it could help through 

 special investigations and advice toward preventing serious losses of 

 forest resources from damage by wood and bark boring insects. 



Recent investigations of logging and manufacturing operations in 

 Mississippi to meet the demand for ash oars, handles, and other sup- 

 plies, required by the war service, showed that one company had lost 

 more than 1,000,000 feet of ash logs through failure to provide for 

 prompt utilization after the trees were cut and thus prevent the 

 attack of the destructive ash-wood borers. 



There is a continued reduction of the heretofore serious losses of 

 seasoned ash and other hardwood sap material from powder post, 

 ^ue to the more general adoption of the methods advised by the bu- 

 reau. This has been accomplished largely through the adoption of 

 methods of management by the manufacturers and shippers with 

 little cr no additional cost. 



By far the most extensive insect-control reconnaissance that has 

 been carried out to date is the " California survey," which was com- 

 pleted during the year. This was organized as a cooperative project 

 in which a number of California lumber companies, the Forest Serv- 

 ice, and the Bureau of Entomology were engaged. The general 

 supervision of the survey was assigned to the assistant forest ento- 

 mologist, Mr. J. M, Miller, who has charge of the Pacific slope field 

 station. 



The territory covered consisted of the pine belt along the western 

 flank of the Sierra Nevada Mountains between the American and 

 Kern Rivers. The results of this survey showed that the loss in 1917 

 from tree-killing beetles on the 1,682,000 acres covered was approxi- 

 mately 27,000,000 feet of merchantable timber with a stumpage value 

 of $60,000. If the recommendations of this bureau are adopted by 

 the Forest Service and private owners and properly carried out, it is 

 certain that a large percentage of this annual loss can be prevented, 



