1911 



GLEANINGS IN BEE CULTURE 



107 



EUROPEAN FOUL BROOD. 



Conditions in Which Bees are Immune or Sus- 

 ceptible. 



BY F. B. CAVANAGH. 



Continued from last ixnue, poae ',':>. 



The most important consideration in es- 

 tablishing either immunity or a cure is the 

 Italian bee, although in my limited experi- 

 ence Cyprians, Carniolans, and Caucasians 

 are all equally good resisters of the disease. 



The leather-colored Italians are not so good 

 as the three-banded yellow Italians; and 

 with me, as a rule, the darker the hybrid the 

 poorer the resistance. Time and again have 

 I seen black or dark hybrid bees filthy with 

 disease, while right beside them were hives 

 of Italians showing scarcely a bad cell. 



Young queens are also important in es- 

 tablishing immunity, as they keep the hive 

 in a strong and vigorous condition; and for 

 some reason their brood will hatch healthy, 

 when that from a poor or black queen would 



COTTONWOOD BUDS, SHOWING BULBS OF 

 PKOPOLIS. 



be diseased. Hence curing black bees of 

 European foul brood is as futile as mending 

 a worn-out automobile tire, and the case is 

 quite as liable to break out again. 



The time of the year and extent of the 

 honey-flow are of great importance, and 

 must have our utmost consideration when 

 applying curative measures. In this local- 

 ity the disease shows worst in May, the 

 main breeding season in which bees are 

 drawing heavily on their stores. At this, of 

 all times, they are susceptible to the disease, 

 and easily infected. 



This is the time also when the "self-cur- 

 ed " colonies of the previous autumn will 

 develop disease from the honey in the hives, 

 if at all. Feeding in itself, at this period, 

 will prevent much of the disease by supply- 

 ing healthy food stores at a time when the 

 colony is at the lowest ebb of vitality, and 

 the time when the bees in the hive are most- 

 ly old, and, consequently, are poor comb- 

 cleaners. If we bridge over this critical part 

 of the season by feeding, these colonies a 

 few weeks later will have estab- 

 lished a condition of immunity 

 when the honey-flow is on and 

 the hive is full of young bees. 



During this critical period is 

 also the time to observe the su- 

 perior condition of the Italian 

 colonies whose young queens 

 have supplied their hives with 

 young bees by laying late in the 

 previous autumn. 



Summing up, the ideal condi- 

 tions for immunity are: 1. 

 Strong hives with young Ital- 

 ian bees and queens and a fair 

 honey-flow, or feed given during 

 the early breeding season. 

 2. Conditions for infection — 

 weak colonies, poor queens, or black stock, 

 and a poor honey-flow, any of which condi- 

 tions will aggravate the trouble. 



Bees can be kept in a strong resistant con- 

 dition just as man's system can be kept in 

 a vigorous condition, which will be resistant 

 or immune to various diseases. That a vig- 

 orous colony may be fed infected honey 

 without contracting the disease, while a 

 weak discouraged colony will develop the 

 disease if even in the vicinity of diseased 

 hives, and probably without having robbed 

 or received any infected honey, is plainly 

 due to the "condition of the colony" and 

 the race of bees. This condition was char- 

 acteristic of my first experience — the weak 

 colonies being attacked by far the worst. 



CURES — WHY THEY SUCCEED AND WHY 

 THEY SOMETIMES FAIL. 



A badly infected apiary of 25 hives which 

 I inspected near Lowell two years ago con- 

 tained nothing but black bees. There was 

 no clover flow that year; and as the trouble 

 had been there for some time previous, the 

 colonies were so badly diseased that I con- 

 demned the entire lot. The McEvoy treat- 

 ment was administered simultaneously to all 

 colonies, each one being shaken twice with 



