GLEANINGS IN BEE CULTURE 



April, 191 





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THE ISLE OF WIGHT DISEASE 



The Mite Causing this Disease Not Yet Found in 

 the United States 



American beekeepers have been much in- 

 terested in the reports that have come from 

 their fellow workers in Great Britain re- 

 garding the losses that come from the Isle 

 of Wight disease, as it is commonly called. 

 So far as is known, this condition does not 

 exist in the United States, and naturally we 

 are not anxious to have it. The findings of 

 Dr. John Eennie and his associates of the 

 University of Aberdeen, reported in Decem- 

 ber, 1920, that the disease is caused by a 

 parasitic mite, Tarmnemus ivoofli, seemed to 

 hold out ultimate hope of some remedial 

 methods, for until the cause was known 

 little could be done on treatment. This in- 

 vestigation is one of the outstanding dis- 



Mite associated with Isle of Wight disease. Figure 



at left male, dorsal view. Figure at right female, 



dorsal view. — (Hirst.) 



coveries of the decade in beekeeping, and 

 great credit is due Doctor Eennie and those 

 who worked with him. 



A recent paper by Stanley Hirst, the Eng- 

 lish specialist in mites, is of interest for 

 two reasons. First, he gives much the best 

 illustrations that have yet appeared of the 

 mites found in bees suffering from the Isle 

 of Wight disease; and, second, he decides 

 that the mite is so specialized in structure 

 that it should be placed in a new genus. It 

 should now, according to Hirst, be called 

 Acarapis ironrli. The illustrations, partly 

 drawn by the artist Tarzi, are especially 

 fine and are here reproduced in part.. These 

 will give an idea of the characteristics of 

 tliis parasite, and would be useful in identi- 

 fication in the event that at any time mites 

 are found in the United States which are 

 susx^ected of being the one which causes the 

 disease which has been so destructive in 

 Great Britain. In the differentiation of 

 various mites the number and position of 

 hairs are important. 



Hirst's descriptions of the mite are tech- 

 nical and they are not given, but any one 

 interested may find them in the June, 1921, 

 number of the Annals and Magazine of 

 Natural History, VII, No. 42 (9th series), 

 pp. 509-519. 



From time to time a considerable number 

 of samples of diseased adult bees have been 

 sent to the Bureau of Entomology for ex- 

 amination and since the announcement of 

 the results from Aberdeen they have been 

 examined for mites; none of them were 

 found to contain specimens of this mite. In 

 case any peculiar cases of disease in adult 

 bees are observed, the Bureau of Entomol- 

 ogy will be glad to receive specimens for 

 examination. Such specimens may be sent 

 in an ordinary queen mailing cage l3ut it will 

 be better to send a larger number, prefer- 

 ably as many as 200, in case any serious 

 condition is observed. 



Mites are sometimes found about the hive, 

 especially in dried pollen and in debris, and 

 in case such material is observed it will be 

 worth wliile to have it examined also. It is 

 not at all probable that Acarapis! irondl 

 would be found in any such place, but now 

 that a mite is found to be causing a disease 

 of bees, it will be well to get all possible 

 information on mites about the apiary. Sev- 

 eral species of mites have already been 

 found in such places as are indicated. 

 Mites are so small that they may often be 

 overlooked, but can often be detected by 

 slight movements in debris. 



Washington, D. C. E. F. Phillips. 



I 



THEIR VALUE WORTH THEIR COST 



A Defender of the Much Maligned Drone Says 

 the Workers Shine up to Him 



On page 151 of March Gleanings, Mr. 

 Aeppler gives the readers of Gleanings a 

 very interesting article relative to the food 

 value of larval food. Without wishing to 

 throw any discredit on the work of Mr. 

 Aeppler, I desire to call attention to one or 

 two details which have a bearing on one of 

 his conclusions. 



In getting the weight of the feed as taken 

 from the cells of drones and of workers, 

 what precautions or signs did he go by to 

 select those of the same age? Did he go by 

 size alone? If he did there is a great chance 

 for error for two reasons. Drone and worker 

 larvae are not of necessity the same age 

 when they are the same size. Again, larvae 

 of the same size are not necessarily of the 

 same age even if of the same sex. Bees 

 flood larvae with food at intervals, and 

 though I have much yet to learn in this re- 

 gard I am inclined to the belief that the 



