SEPTEMBER 1, 1916 



783 



GENERAL CORRESPONDENCE 



CURES AND IMMUNITY OF THE ISLE OF WIGHT DISEASE 



BY GEO. W. BULLAMORE 



"Labor in vain and lost cash" is the usual 

 result of attempts to cure bee diseases by 

 means of drugs; nor do I think we are justi- 

 fied in hoping for any other result. The 

 physician has attained some success in the 

 treatment of human ailments; but the drugs 

 administered are usually for the alleviation 

 of tlie more distressing symptoms. Careful 

 nursing and dieting then bring about the 

 cure. In a few diseases, drugs, such as 

 certain compounds of arsenic, have a direct 

 effect on the cause ; but for successfully 

 stamping out an epidemic it is necessary to 

 resoi-t to methods for the prevention of 

 contagion. 



The sudden death in winter of a large 

 number of stocks which were i:)acked down 

 in the autumn in apparently good condition 

 after producing surplus is a symptom of 

 the Isle of Wight disease which does not 

 offer opportunities for treatment. At cer- 

 tain times, however, bees are to be seen 

 crawling with the bowel heavily laden with 

 pollen residues. Attempts are often made 

 to treat this manifestation of disease by 

 means of aperient medicines administered in 

 sugar syrup. Sometimes success is claimed ; 

 but we know very little about the action of 

 drugs on insects, and it is not unlikely that 

 the result would have been the same had the 

 drug been omitted from the syrup. A nat- 

 ural honey-flow may also bring about the 

 cessation of crawling. When syrup or di- 

 lute honey is being administered to the bees, 

 excess of liquid is often passed off thru the 

 intestines. When nectar is being gathered, 

 some of the water finds its way to the 

 bowel. The resultant flushing relieves the 

 system of toxins (poisons produced by 

 disease germs) which cause the symptom, 

 but the disease itself remains. 



All the reported cures of Isle of Wight 

 disease appear to be records of the disap- 

 pearance of this crawling symptom, and to 

 have been brought about either by feeding 

 with syrup or dilute honey, or by means of 

 a sudden stoppage of brood-rearing. The 

 giving of sulphate of iron in the food, 

 sprinkling the combs with sulphur and 

 other fungicides, and painting the inside 

 of the hive with creosote, are operations 

 known to destroy brood, and have been 

 suggested as cures. When brood-rearing 

 ceases suddenly, the vital drain of gland 

 secretion from the workers is arrested ; and, 

 in addition, the excess moisture from the 



food will now pass to the bowel. CraAvling 

 due to weakness and parasitic intoxication 

 will then cease in a few days. For some 

 such reason an apparently immune stock in 

 an attacked ajaiary often proves to be 

 queenless. 



Attempts have been made to find a strain 

 of bees that would resist Isle of Wight 

 disease in much the same manner as the 

 Italian race resists European foul brood. 

 It is no test of resistance in this latter case 

 if we merely change the queen of a foul- 

 broody stock without allowing a period of 

 queenlessness. Neither do we give the new 

 race a fair trial when we requeen a stock 

 showing the crawling symptom of Isle of 

 Wight disease. In both cases the bees are 

 swamped with disease from the commence- 

 ment of the experiment. When Italian bees 

 have had a fair chance I think that there is 

 some evidence that they are the last to be 

 affected, and that they moi'e often recover 

 temporarily. This suggests some slight de- 

 gree of resistance rather than actual im- 

 munity ; and to make the distinction clear a 

 few lines on the nature of epidemic disease 

 may be of use. 



The breaking-up of organic matter into 

 simpler compounds in nature is brought 

 about by the agency of fungi, among which 

 we include minute organisms known as 

 bacteria. Many of the bacteria have rest- 

 ing forms, known as spores, which tide 

 them over periods of adversity. Others 

 depend for their continued existence on a 

 continuity of food supply. 



While life is present, the organic matter 

 can resist the attacks of the majority of 

 these bacteria (it possesses immunity), but 

 certain forms have power to overcome the 

 resistance of the living host, and a condi- 

 tion of parasitism results. Should the bac- 

 terial growth prove harmless, or should it 

 liandicap the host but slightly, the relation- 

 ship is one of tolerance. But the growth 

 often results in the production of poisons 

 "known as toxins, and these produce disease 

 and death in a susceptible host. In much 

 the same manner minute animal parasites 

 maj"^ produce disease. 



Diseases were originally much more local 

 than they are at the present day. The re- 

 sult was, therefore, that the constant attack 

 on a limited number of hosts meant the 

 extinction of the hosts, and, in consequence, 

 of the disease for lack of material. Other- 



