BUREAU OF ENTOMOLOGY. 415 



in order to prevent the further spread of this serious disease of adult 

 bees. 



Work has been continued on the examination of diseased or ab- 

 normal adult bees from all parts of the United States. During the 

 active season of 1922 samples to the number of 184 were examined, 

 but just as in this work for 1921, no samples were obtained in which 

 the mite causing the Isle of Wight disease was found. During the 

 season of 1923 this work is being continued, and so far the results 

 are still negative for bees from the United States. The records of 

 the examinations for 1922 are incorporated in the above-mentioned 

 manuscript on the distribution of the Isle of Wight disease. 



On the basis of the negative findings in the search for the Isle of 

 Wight disease in the United States, as stated in the last report, a bill 

 was introduced into Congress to prohibit the importation of adult 

 bees, except from countries in which it is determined that no diseases 

 dangerous to adult bees exist or for experimental or scientific pur- 

 poses by this department. This bill W2»s passed by Congress in 

 August, 1922, and was approved by the President on August 31, 1922. 



In accordance with the provisions of this act, regulations have 

 been approved by the Secretary of the Treasury and the Secretary of 

 Agriculture which permit the importation of adult bees without 

 restriction from the Dominion of Canada and which further define 

 the methods by which adult honeybees may be imported for experi- 

 mental and scientific purposes. Additional sj^ecial rules on this suli- 

 ject were more recently approved by the Secretary of Agriculture. 

 Provision is made for importations necessary to prevent any de- 

 terioration of the stock of the bees in this country and for providing 

 all scientific workers with necessary imported breeding stock. Since 

 the regulations and special rules were not adopted until near the 

 close of the fiscal year, no importations could be made until after 

 the close of the year, but arrangements were made for the importa- 

 tion of some breeding stock under the provisions of the regulations. 



A manuscript has been prepared dealing with the morphological 

 structures involved in the Isle of Wight disease, with a discussion of 

 the respiratory system of the normal bee. This clears up many ques- 

 tions resfardinff this disease, which is concerned solelv with the 

 respiratory system. 



The investigations on the etiology of the brood diseases of bees 

 have been continued. A paper has been submitted for publication 

 in which the results of the biochemical study of the larva before and 

 at the time of death by American foulbrood are discussed. It is 

 found that the development of the causative organism and the con- 

 sequent death of the larva do not occur until the sugar content of 

 the larval intestine is quite low, and that this is the cause of the 

 marked regularity in the time of death and in the resulting uniform 

 positions of the dead larvae which are characteristic of this disease, 

 and in marked contrast to conditions found in the other disease of 

 the brood of bees, European foulbrood. The results of tliis inves- 

 tigation of the chemistry of the larvse were correlated with the 

 biochemical and cultural characteristics of the causative organism. 

 In order that this investigation might be carried out, it was neces- 

 sary to devise somewhat new methods of analysis, and thus for the 

 first time it was established that there is a considerable unassimi- 

 lated sugar content in the developing larva. This work was cor- 



