Spring cleaning

Demolition experts don’t get much credit - plaudits always go to the builder, yet without the work of the demolition crews there would soon be no space to build.

Bees have exactly the same problem: They fill their home with delicate white comb which is used to store honey and pollen and to raise brood, and they eventually run out of space.

Raising brood is messy; every time a new bee emerges from its cell it leaves behind the thin skin of its cocoon. The house-bees quickly clean up any loose material but rather than scrape every last piece of cocoon off the cell walls they simply skim the surface with a bit more wax and polish it ready for the queen to re-lay.

In the course of a year a brood cell may be skimmed and polished 17 times, each time getting a little bit darker and a little bit smaller. Smaller cells means smaller bees, so it’s not surprising that in the wild, bees soon abandon old brown comb and make new white comb for the queen to lay in – provided there’s room!

This is where the demolition experts come in. Little silvery-brown moths lay their eggs in old brood comb and soon the caterpillars are munching their way through the comb, turning it to dust within a few weeks and creating space for the bees to make new comb.

You would think beekeepers would like wax moths – nature’s little demolition experts, but you would be wrong. The caterpillars are routinely squashed, frozen, or infected with lethal bacteria. The reason for the slaughter is simple – many beekeepers force their bees to keep using old brood comb, often for years on end, so that the comb is as black as tar and as thick as cardboard – and perfect for food for wax moths!

The obvious thing to do is remove the old comb, but that’s not so easy using standard hives. At best a diligent beekeeper would change the brood comb every 3 years; hardly surprising there's an ongoing battle with the demolition crew.

I don’t use standard hives so most of my comb is is less than 12 months old. Clean comb means less bee disease as well as bigger bees, but there is a downside - every spring I have dozens of old frames of comb that need cleaning, which takes hours of work.

Of course, I could spare myself the effort and just leave them out for the wax moths!