I02 



in 1904, and recognized as a new disease in this country, though 

 it must have been here for some time prior to that date, accord- 

 ing to the bulletin. 



No practical control of the disease is known. Search is, 

 however, being made for native and foreign chestnuts resistant 

 to the blight in the hope of finding a tree suitable for partially 

 replacing the rapidly disappearing stands of chestnut timber. 

 Lumber from blight-killed trees is equal to that cut from live 

 trees if salvaged before deterioration sets in. The increased 

 use of such lumber is important in order to prevent serious loss. 



Ever since fruit trees have been sprayed with arsenicals, 

 beekeepers have been much interested in the effects of the 

 practice on the mortality of honeybees. They have long felt 

 that many bees were poisoned as a result of spraying, but until 

 recently few systematic investigations have been conducted to 

 determine whether or not honeybees are actually injured by 

 these chemicals. 



In the hope of finding definite answers to some of the questions, 

 so long debated, the entomologists of the United States Depart- 

 ment of Agriculture planned and conducted a series of experi- 

 ments, the results of which are discussed in Department Bulletin 

 No. 1364-D. The investigations, extending over a period of 

 three years, were made along three lines: (i) The effect on honey- 

 bees of spraying fruit trees in full bloom; (2) the effect on 

 honeybees of spraying the trees at the customary time, after 

 most of the petals have fallen; and (3) a determination of the 

 minimum amount of arsenic required to kill the bees in confine- 

 ment. 



After one season's work in two States, it was ascertained that 

 spraying during full bloom was detrimental to bees. After 

 three seasons' work on the problem, in four States and five 

 localities, it was determined that spraying at the customary 

 time under nearly ideal conditions was not injurious to the 

 bees; but nearly ideal conditions seldom occur. 



The minimum fatal dosage of arsenic per bee, according to 

 laboratory determinations, is between 0.0004 ^^id 0.0005 milli- 

 grams. 



The subject of poisoning bees is very large and of vital interest, 

 not only to beekeepers but to everyone who is interested directly 



