Mites Injurious to Domestic Animals. 99 



the host. Occasionally a few adult female mites may be seen 

 wandering about on the dead body of their host. Rennie states 

 (" Bee World," May, 1921, p. 144) that adult females of the mite 

 may be found creeping amongst or clinging to the hairy covering 

 of infected bees, and that when bees carrying such mites move 

 about in the cluster, the mites are transferred from bee to bee. 

 Fertilisation had, no doubt, already taken place before the female 

 mite left the inside of the tracheal tubes of its host. It is too early 

 as yet to be able to estimate the exact degree of importance 



FIG. 82. 



(a) Larva of Acarapis woodi. (b) The same in the egg-shell. 

 (After Hirst, Ann. Mag. Nat. Hist., June, 1921.) 



of the discovery of this Tarsonemid mite as an internal parasite 

 of the honey bee. It is probable, however, that it is the causal 

 agent of the deadly malady usually called " Isle of Wight Bee 

 Disease." As mentioned above, the protozoon Nosetna apis was 

 once thought to be the cause of this disease, but apparently the 

 disease set up by it is a distinct one. The possibility that other 

 diseases with similar symptoms may occur should also be borne in 

 mind, for bees are sometimes found crawling and dying in large 



H 2 



