But when I attempted the next link in the chain (to wit) What caused the death of this brood just at this stage of development? I was obliged to stop. Not the least satisfaction could be obtained. All inquiries among the bee-keepers of my acquaintance were met with profound ignorance. They had "never heard of it!" No work on bees that I consulted ever mentioned it.
Subsequently, I had more stocks in the same situation. I found, whenever the disease existed to any extent, that the few bees matured were insufficient to replace those that were lost; that the colony rapidly declined, and never afterwards cast a swarm!
REMEDIAL EXPERIMENTS.
As for remedies, I tried pruning out all those combs containing brood, leaving only such as contained honey, and let the bees construct new for breeding. It was "no use," these new combs were invariably filled with diseased brood! The only thing effectual was to drive out the bees, into an empty hive. In this way, when done in season, I generally succeeded in rearing a healthy stock. But here was a loss of all surplus honey, and a swarm or two that might have been obtained from a healthy one.
PUBLIC INQUIRY AND ANSWERS.
I had so many cases of the kind, that I became somewhat alarmed, and made inquiry through the Cultivator, (an agricultural paper,) as to a cause, and remedy, offering a "reward for one that would not fail when thoroughly tested," &c. Mr. Weeks, in answer, said, "that cold weather in spring chilling the brood was the cause." (This was several years prior to his article in the N.E. Farmer.) Another gentleman said, "dead bees and filth that accumulated during winter, when suffered to remain in the spring, was the cause." A few years after, another correspondent appeared in the Cultivator, giving particulars of his experience, proving very conclusively to himself and many others, that cold was the cause. Having mislaid the paper containing his article, I will endeavor to quote correctly from memory. He had "three swarms issue in one day; the weather during the day changed from very hot to the other extreme, producing frost in many places the next morning. These swarms had left but few bees in the old stocks, and the cold forced them up among the combs for mutual warmth; the brood near the bottom, thus left without bees to protect it with animal heat, became chilled, and the consequence was diseased larvæ." He then reasoned thus: "If the eggs of a fowl, at any time near the end of incubation, become chilled from any cause, it stops all further development. Bees are developed by continued heat, on the same principle, and a chill produces the same effect, &c.; afterwards, other swarms issued under precisely similar circumstances; but these old stocks were covered with a blanket through the night, which enabled the bees to keep at the bottom of the hive. In a few days, enough were hatched to render this trouble unnecessary. These last remained healthy." He further says, that "last spring was the first time I ever knew them to become diseased before swarming had thinned the population. The weather was remarkably pleasant through April. The bees obtained great quantities of pollen and honey, and by this means extended their brood further than usual at this season. Subsequent chilly weather in May, caused the bees to desert a portion of brood, which were destroyed by the chill."
Now this is reasoning from cause to effect very consistently.
ANSWERS NOT SATISFACTORY.
Had I no experience further than this, I should, perhaps, rest satisfied as to the cause, and should endeavor to apply the remedy. Several other writers have appeared in different papers, on this subject, and nearly all who assign a cause have given this one as the most probable. Now I have known the chrysalis in a few stocks to be chilled and destroyed by a sudden turn of cold weather, yet these were removed by the bees soon after, and the stocks remained healthy. To me the cause assigned appears inadequate to produce all the results with the larvæ. After close, patient observation of fifteen years, I have never yet been wholly satisfied that any one instance among my bees, was thus produced.
A CAUSE SUGGESTED.