UNDERSTAND BEES. PROTECT LIFE.An independent encyclopedia
apisanitas.HONEY BEE HEALTH
Predators

Wax moth

Galleria mellonella and Achroia grisella

Severity : Moderate Warm season; summer comb storageReview in progress
Topic symbol

Key points

  • Two moths whose caterpillars eat wax: the greater and lesser wax moth.
  • A strong colony defends itself; weak colonies and stored combs are at risk.
  • Silk tunnels, cocoons glued to woodwork, combs reduced to debris.
  • Store cold, dry and in the light; freeze combs before storage.

Wax moth is a pest, not a disease. It takes advantage of weakened colonies and, above all, of combs stored by the beekeeper.

The two species

  • Greater wax moth (Galleria mellonella): grey-brown moth about 15 to 20 mm long; its caterpillars can destroy a comb within days in summer1.
  • Lesser wax moth (Achroia grisella): smaller and silvery; its caterpillars tunnel under cappings and cause “bald brood”, lines of uncapped pupae.

Signs

  • Silk-lined tunnels through the combs.
  • Black, grainy droppings on combs and the floor.
  • Tight white cocoons glued to woodwork, gouging hollows into the frames.
  • In advanced cases, combs reduced to a mass of silk and debris.
Photo needed — Damaged stored comb: silk tunnels and cocoons lined up along the top bar.

Do not confuse with

Small hive beetle larvae spin no silk and only have three pairs of legs at the front. See the Small hive beetle factsheet.

Prevention in colonies

  • Keep colonies strong and unite weak ones.
  • Do not leave too many empty combs relative to the population.
  • Remove old dark combs, which caterpillars prefer.

Protecting stored combs

  1. Sort combs: render old dark combs.
  2. Freeze combs before storage to kill eggs and larvae, for example 48 hours at domestic freezer temperature.
  3. Store in a cool, dry, ventilated room, in the light, with boxes criss-crossed or spaced.
  4. Some countries authorise products based on Bacillus thuringiensis (aizawai strain) against wax moth: check their status where you live1, 3.

References

  1. Kwadha C.A. et al. (2017). The biology and control of the greater wax moth, Galleria mellonella. Insects 8(2): 61. doi.org
  2. Ellis J.D. et al. (2013). Standard methods for wax moth research. The COLOSS BEEBOOK, Vol. II. Journal of Apicultural Research 52(1).
  3. FAO, IZSLT, Apimondia, CAAS (2021). Good beekeeping practices for sustainable apiculture. FAO Animal Production and Health Guidelines No. 25.

Updated : October 8, 2026
Written by : Apisanitas editorial team
Reviewed by : Review in progress