228 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



mer (1916) which, it is believed, will result in enough work being 

 done next winter to control these insects on Long Island and thus 

 set an example for similar work in all of the Northern and New 

 England States. 



Insect damage to Australian pine plantations in Florida. — 

 Complaints received from planters and owners of the so-called Aus- 

 tralian pine along the coast of subtropical Florida were investigated 

 in May, 1916. It was found that very extensive damage to the young 

 trees was caused by a flatheaded borer which normally breeds in the 

 red mangrove. Methods of control and prevention were recom- 

 mended which should bring early relief from the trouble. 



Damage to the woodwork of buildings by white ants. — More 

 than the usual number of complaints of damage to the woodwork of 

 buildings by white ants, or termites, have come in during the year 

 from this and other countries. Fifteen cases of more or less serious 

 damage to buildings, including private residences, business houses, 

 a church, a railroad station, and the old building of the United States 

 Bureau of Engraving and Printing, were reported. Many documents 

 in the building last mentioned were damaged or destroyed. Often it 

 has been necessary to advise the reconstruction of foundations and 

 floors to prevent further damage, but in every instance in which the 

 advice of the bureau has been followed no further trouble has been 

 experienced. 



Experiments with insecticides. — The discovery was made that 

 the addition of sodium arsenate to the ordinary kerosene emulsion 

 at the rate of 1 pound to 2 gallons of water used to dilute 1 gallon 

 of the stock emulsion produced a most effective mixture to kill certain 

 bark and wood boring insects. It has been found by experiments and 

 the subsequent examination of wood-boring larvae that the poisoned 

 emulsion is much more effective than the pure emulsion and that it 

 is especially adapted for combating certain wood-boring larvae for 

 which heretofore there has been no practical remedy. 



Experiments with various chemical substances to determine their 

 relative effects in preventing attack by wood-boring insects in crude 

 and finished wood products showed that various proportions of 

 creosote plus the kerosene were very effective when thoroughly 

 applied to all parts. 



Experiments conducted with poisoned kerosene emulsion and kero- 

 sene and creosote, to determine the effect on various wood and bark 

 boring insects which attack living trees and crude wood products, 

 showed that these insecticides were not effective against broods of 

 barkbeetles, but that both the poisoned kerosene and the cresote- 

 kerosene solutions were effective against the hickory and locust 

 borers, the former being relatively the more effective, while in the 

 case of the chestnut-tree borer the poisoned emulsion only was 

 effective. 



Two new accidentally introduced pests. — Special attention has 

 been given to a study of two tree pests introduced shortly before the 

 plant quarantine act became operative — the European pine-shoot 

 moth and the European pine sawfly — and caged living trees of vari- 

 ous kinds have been utilized in determining many of the obscure 



