Humped Brood (Laying Workers)
Lexikon
Bullet brood is the name for the characteristic, irregularly domed brood pattern that develops when drone larvae grow up in worker cells that are actually too small for them.
Bullet brood is the name for the characteristic, irregularly domed brood pattern that develops when drone larvae grow up in worker cells that are actually too small for them. Because a drone larva needs more space than a worker larva, the bees have to raise the flat capping into a hump-like dome to close the cell. It is this bumpy, uneven appearance of the affected comb area that gives it its name.
The cause is always disturbed egg laying: either an old queen whose supply of semen is used up, a young queen that was never properly mated because of bad weather, or a colony with no queen and no young brood in which individual workers begin to lay instead. In all three cases fertilized eggs are missing, so that only drones emerge, which are also often smaller than normal drones.
Colonies with bullet brood from laying workers are considered beyond saving in practice, because usually several workers take part in egg laying at the same time and a newly introduced queen is not accepted. It is common practice to shake out such a colony a few meters away from the apiary so that the bees that can still fly beg their way into neighboring colonies, while some of the laying workers stay behind; because they can fly as well, success is uncertain.