ON ISLE OF WIGHT DISEASE IN HIVE BEES — ETIOLOGY. 189 



yielded four crates of sections and had fifteen pounds of stores left in the hive. The 

 owner writes, " I am pleased to state there are no signs of any trouble." Seven 

 bees were supplied from the stock, and of these five were harbouring Tarsonemus 

 at the same date. 



About the middle of October a slight amount of crawling was observed in this 

 stock, but weather conditions have prevented further observations. At the end 

 of October a sample of bees supplied was found heavily infected. The stock 

 continues under observation. 



Notes on Stock Records. 



R. No. 1. — In about six weeks after the infection was first discovered, but not 

 until the incidence of infection had risen to over 89 per cent., did visible signs of the 

 presence of the disease appear. 



No. 44. — ^This stock certainly developed an infection of Tarsonemus within the 

 period of 11th April to 26th May, i.e. about six weeks. The examinations showed 

 a rapid spread of Tarsonemus within the colony, so that in a little over four months 

 from the arrival of the stock the incidence of infection was 97 per cent. And yet 

 crawling was never in evidence until near the end. 



No. 61. — This stock shows a striking parallel to the previous. Within the three 

 months from 30th May to 30th August, the infection rose to about 80 per cent., 

 and only now did crawling symptoms appear, although meantime the stock had 

 visibly declined in numbers. 



No. A. Ch. — Examination of bees from the original apiary in September, which 

 were showing suspicious signs, showed that they too were infected with Tarsonemus. 

 It appears probable that this stock was infected before leaving the original apiary, 

 and from the fact that on 17th July the percentage of infection was so very high 

 it would appear that the distribution of Tarsonem,us was well established, though 

 probably of recent origin. 



Glasgow, I. — This stock was known to have a definite infection on the 8th July, 

 which rose at the end of October to 27 per cent., without disease signs appearing. 

 This is a case in which the spread of the disease within the stock is progressing 

 with relative slowness. 



Glasgoiv, P. — This is a similar case to the foregoing in that the spread of infection 

 has been slow, and in which the ordinary disease symptoms have never appeared. 



No. 62. — Nearly six weeks in an infected apiary elapsed before this clean stock 

 was found to be harbouring Tarsonem,us. After four and a half months from the 

 time the presence of Tarsonem,us was first discovered the incidence had increased 

 to over 92 per cent., and no disease symptoms have ever been seen and the stock 

 appears in a prosperous condition. 



No. 60. — This is a stock which, although found to have Tarsonemus present in 

 August, appears to have lost the infection. 



