Wax moths can
be a terrible problem to bee hives if allowed to get out of hand and
will destroy brood comb in a very short time if unchecked. There are
some simple steps to prevent the damage, but first it might be simpler
to discuss the life cycle to understand where the problem comes from.
A normal healthy hive will keep wax moth under control by ejecting the larvae, but weakened hives with small populations can be overcome by wax moth infestations destroying the brood comb, ultimately destroying the hive.
There are two varieties of moth which take delight in dining on wax the 'Greater' and also the 'Lesser' Wax Moth the greater wax moth is a mottled grey in colour approx 1 -1B= inches in length while the lesser is smaller and slimmer approx B= inch in length and white/silver. As all moths, they prefer night time to mate and lay eggs. (Photos are available in our picture gallery.)
Most wax moths are seen in early summer in our area, and we see them under the overhang of hive roofs, out of the daylight, when the hive is disturbed they take off quickly and disappear into the trees.
Preferring to work in the dark the moths enter the hive through top entrances left unscreened and unguarded by the bees, perhaps a sudden cold snap making the bees cluster, and lay eggs in cracks unavailable to the bees. These hatch in due course and the grey larvae begin feeding on wax and hive debris, tunneling just under the cell caps and feeding on the discarded cocoons left by the bees, leaving behind an extremely sticky white web, similar to spiders web but almost impossible to pull apart. So perhaps they are misnamed and should be called Cocoon moths?
With a little care wax moth can be outwitted and the damage they do can be prevented.
First, the practice of top entrances should be examined, provided they
have screening then there will be no problem. Leaving a big hole in
the inner cover, then a badly fitting roof, is just asking for trouble.
Or even worse those holes drilled in the top of boxes allowing the bees
a second entrance are a real problem. Apart from pollen in the honey,
a cold evening and the bees pull down and form a cluster leaving that
entrance unguarded, easy pickings for the wax moth, as they will fly
in cooler conditions than bees.