Isle of Wight Disease in Hive Bees. 31 
(6) EXAMPLE OF NATURALLY OCCURRING OUTBREAK OF ISLE OF WIGHT 
DISEASE, SHOWING SPONTANEOUS RECOVERY. 
CRAIBSTONE APIARY. 
On 4th June 1915, three strong stocks of bees imported from Devonshire 
were placed in this newly constituted apiary and housed in perfectly fresh 
hives. During the fine weather of June they were very prosperous, each 
stock swarming once and one of them twice. The swarms were hived 
separately. Three races were represented, viz. pure Italian, pure Carniolan 
(queen imported from Austria in 1914), and ordinary black bees. 
Symptoms of Isle of Wight disease made their appearance on 30th June, 
and continued, with fluctuations, till near the end of August. All the 
stocks and swarms were affected more or less, but the heaviest mortality 
occurred in the blacks (D4). Three of the seven stocks died out owing to 
their failure to mate the virgin queens. In all three cases drone breeders 
were developed. On 22nd September four stocks survived and no symptoms 
of Isle of Wight disease were apparent, either in the behaviour of the 
bees, which was perfectly normal, or in the condition of their internal 
organs. At no stage of the disease were spores of Nosema found, although 
repeated examinations of’ the contents of the alimentary canal were 
made. 
While the disease was at its height the number of affected bees was 
very great. Their behaviour was of the usual character, and the walk leading 
from the hives was littered with crawling bees to a distance of at least 
25 yards. Heaps lay on the flower-beds, and a low box-hedge was full of 
bees incapable of flight. | 
The mortality was, in consequence, very considerable, and the weather 
conditions were exceedingly unfavourable to bee life. The recovery is 
therefore all the more notable. 
On 22nd September one of the stocks (D4) was decidedly weak. It was 
headed by a young queen, had brood on two combs and plenty of store for 
the number of bees. This is the stock which had the heaviest mortality 
during the crawling period. Two other stocks (Al and C3) were in 
excellent condition for wintering, headed by young queens, populous as 
to bees, and with plenty of stores. The fourth stock (B2) is the only one 
now that is not headed by a queen of this year. Possibly on this account, 
and also on account of heavy losses during the crawling period, this stock 
is also rather short of bees. The queens in D4 and B2 are black, C3 has 
a young Carniolan queen. A1, originally pure Italian, is now filled with 
dark bees, the offspring of a young queen. 
