The Occurrence of Diseases of Adult Bees, II. 7 



proprietary compounds and drugs, and unfortunately some of these 

 nave received the indorsement of certain prominent beekeepers, al- 

 though Eennie has given repeated warnings against reliance on such 

 unfounded claims. None of the claims made for chemical treatments 

 can as yet be accepted as valid, and apparently no specific treatment 

 has yet been found. Doctor Rennie has devised a trap for the catch- 

 ing of crawling bees as they leave the hive, but to what extent it is 

 beneficial can not be determined from a reading of the literature. 

 From the nature of the cause of the disease a hopeful line of attack 

 has been suggested through some gas which will penetrate the tra- 

 cheae and kill the mites but leave the bees unharmed. Whether a bee 

 is worth saving which has mites, dead or alive, in its tracheal trunks 

 is questionable. The most promising method of attack seems to be 

 the elimination of the infested bees and the rearing of a large force 

 of young bees to take their places, thus reducing the infestation, as 

 has been urged by both Eennie (5^) and Morgenthaler (4-4). Ren- 

 nie {5S) emphasizes the necessity for swarm control measures, since 

 swarms are especially prone to show crawlers soon after issuing. He 

 says (p. 74) : 



I lay special emphasis on rational and intelligent management, because I am 

 convinced that much of the loss which has occurred in the past has given to the 

 disease a gravity which is not inherent in it, and has been due to lack of exact 

 knowledge on the part of competent beekeepers in the one case and to unsatis- 

 factory beekeeping in addition in the other. 



Such a method of control is far more promising for the develop- 

 ment of beekeeping in the infested regions than one based merely on 

 the destruction of the mites. It is identical in theory with the meas- 

 ures for the control of European f oulbrood used in the United States. 



Rennie (67), in his presidential address before the Apis Club, 

 April 7, 1923, discusses the treatment of affected colonies but does 

 not give any definite directions. He seems to entertain the hope of 

 the eradication of the disease from Great Britain. 



EFFECT OF CLIMATE. 



The effect of climate on the propagation of the mite Acarapis 

 woodi has not been studied, and there are no data from which one 

 dares draw conclusions. Since both severe and chronic cases of the 

 disease exist, it may be concluded that some environmental factor 

 may have an influence on the severity of the disease, but it is not indi- 

 cated that these factors are those of climate. Severe cases of the dis- 

 ease have now been described in Great Britain, France, and Switzer- 

 land, and it is certain that almost any climate encountered in any of 

 these countries may be duplicated somewhere within the borders of 

 the United States. To assume that the disease would not do damage 

 here if it were introduced, because of climatic differences, is ex- 

 tremely dangerous, since absolutely nothing has been learned of the 

 influence of climate on the disease. 



DAMAGE. 



The damage resulting from the Isle of Wight disease is a subject 

 which it is extremely difficult to discuss at this distance. Reports 

 have varied greatly, all the way from complete destruction of single 



