Agriculture Reference
In-Depth Information
Identifying wax moth
Identification is easy as, apart from the death's head hawkmoth that is seen only rarely
in colonies in hot countries, the wax moth is likely to be the only moth around. They
are silvery-grey/brown, dull and ordinary and come in two sizes.
First, the greater wax moth (
Galleria mellonella
) (1.3-1.9 cm or ⁄-¾ in long) is usually
found in most beehives, and the bees normally repair any damage it causes as soon as it
appears. It is for this reason that most beekeepers are unaware of it until the bees lose
their ability to defend themselves and the moth larvae take over.
The problems this moth causes in warm countries are more acute because such
conditions favour continuous reproduction. If you live in a warm climate, keep supering
up to the minimum required; otherwise, I found that the wax moth will take over in
the top unused super where there are few bees to stop them. The female lays her eggs in
small crevasses in the hive, and these hatch out into white grubs with a brown end. The
lesser wax moth (
Achroia grisella
) is smaller (see Photograph 7 in the colour photograph
section of this topic) and more silvery in appearance, and its larvae are correspondingly
smaller than those of the greater wax moth.
Damage
The grubs move through the comb, eating honey, pollen and beeswax. The tunnels they
make through the comb are silk lined and full of frass. These tunnels are easily seen
and are just the beginning (see Photograph 8 in the colour photograph section of this
book). When they have grown (up to about 3 cm (1¼ in) for the greater wax moth)
the grubs will hollow out a shallow, boat-shaped depression in the woodwork, spin a
cocoon and pupate. They do this in large numbers and, if you are unfortunate enough
to see this, you will know you have left things very late. The smaller moth larvae usually
pupate singly. By this stage, the comb will have been reduced to almost nothing and will
be held together by moth silk rather than by anything else. This is a horrible sight.
When surprised, both moths remain still, hoping not to be seen. As soon as you try to
kill them, however, they will start to move rapidly.
