43 



This parasite breeds within the bee and is confined to an 

 extremely hmited, but very important region of the breathing 

 system — the first pair of tracheae of the thorax. The multi- 

 phcation of the mite causes this to become either partially 

 or wholly obstructed. In the latter case the bee dies at once, 

 while in the former, being unable to fill the air sacs which 

 permit of flight, the bee is reduced to crawling (one of the 

 symptoms of the disease). In this case also the fseces are 

 not evacuated, as normally this is accomplished on the wing, 

 and hence arises a congested condition of the bowel and a 

 consequent staining of the combs, hive front and alighting 

 board (another marked symptom of the disease). 



Acarine Disease in Summer.* 



Since our knowledge of Acarine Disease is steadily advanc- 

 ing it is probably more satisfactory not to offer advice beyond 

 that applicable to the present season. 



First Signs of Disease. — If a stock begins to show signs of 

 listlessness and works indifferently, if the bees come up and 

 loiter on the tops of the frames when the hive is opened, or 

 if an excess of brood for the number of adult bees is notice- 

 able, the bee-keeper will do well to have the bees tested for 

 the presence of Acarine Disease. The Ministry of Agriculture 

 will do this for a nominal fee. It should be noted that when 

 '' crawhng " from this disease has become an obvious feature 

 in a stock, the proportion of affected bees is already 

 dangerously high and the degree of infestation within the bees 

 is past remedy. Therefore, do not wait for the appearance 

 pf " crawlers." Act at once. 



It cannot be too strongly emphasised that from the practical 

 standpoint the most important thing for the bee-keeper in 

 relation to this disease is to prevent stocks remaining 

 stationary or going down in numbers of bees. He must bear 

 in mind that, viewed practically, the control of Acarine Disease 

 is a problem of counteracting the spread of a destructive 

 parasite from bee to bee. "While he may not be able to do 

 this directly, the bigger the stock built up at the critical time 

 the less important the parasite becomes from his point of 

 view. 



The secret of success in management of the disease in 

 summer is therefore to work for the maximum of young 

 foragers at the time of the honey flow. 



In the writer's opinion the readiest way in which this can 

 be effected is to head all doubtful stocks with this year's 

 queens as early in the sea-son as possible. 



Remember that such a queen can produce bees faster than 

 disease can destroy them. 



* Eeprinted from a leaflet published by the Aberdeenshire and Kin- 

 cardineshire Bee-Keepers' Association and written by John Eenn:e, D.Sc, 

 P.E.S.E., Lecturer in Parasitology, Universit^y of Aberdeen. 



