In a hive thus left without bees to interfere, the worms will increase to one-half or two-thirds larger than where their right to the combs is disputed. In one case they often have their growth, and actually wind up in their cocoon when less than an inch in length: in the other they will quietly fatten till they are an inch and a half long and as large as a pipe-stem.
When first hatched from the egg, it requires very close inspection to see them with the naked eye. The rapidity of growth depends on the temperature in which they are, as much or more than their good living. A few days in hot weather might develop the full-grown worm, while in a lower temperature it would require weeks and even months in some cases, perhaps from fall till spring.
The worm, after spinning its cocoon, soon changes to a chrysalis, and remains inactive for several days, when it makes an opening in one end and crawls out. The time taken for this transformation is also governed by the temperature, although I think but few ever pass the winter in this state. It is a rare thing to find a moth before the end of May, and not many till the middle of June; but after this time they are more numerous till the end of the season.
FREEZING DESTROYS WORMS, COCOON AND MOTH.
It is pretty well demonstrated that the moth, its eggs, larvæ and chrysalis cannot pass the winter without warmth of some kind to prevent their freezing to death. The following facts indicate this. I have taken all the bees out of a hive in the fall, and without disturbing the comb or honey, put it in a cold chamber where it could freeze thoroughly. In the following March bees were again introduced, and when not on a bench with some other stock that had worms, not a single instance in forty cases has ever produced a worm before the middle of June, or until the eggs of some moth matured in another hive has had time to hatch. I have sometimes, instead of putting bees in these in March, kept them till June for swarms, perfectly free from any appearance of worms!
But it is altogether a different thing with our hives in which bees are wintered; they are seldom or never entirely exempt! Perhaps it is impossible to winter bees without preserving some eggs of the moth or a few worms at the same time. The perfect moth perhaps never survives the winter; the only place that the chrysalis would be safe, I think must be in the vicinity of the bees--and a good stock will never allow it there--but eggs, it would appear, are suffered to remain. In the fall, at the approach of cold weather, the bees are apt to leave the ends of the combs exposed; the moth can now enter and deposit her eggs directly upon them; these, together with what are carried in by means before suggested, are enough to prevent losing the breed. The warmth generated by the bees will keep these eggs from freezing and preserve their vitality. When warm weather approaches in the spring, those nearest the bees are probably hatched first, and commence depredations and are removed by the bees. As the bees increase and occupy more comb, more are warmed up and hatched. In this way, even a small family of bees will hatch, and get rid of all the eggs that happen to be in their combs, and not be destroyed. This is the time that the apiarian may be of service in destroying the worms, as the bees get them on the floor.