Wax moth
Less a disease than a symptom — wax moth rarely brings down a strong colony on its own, so a bad infestation is usually the first sign that something else (a queen problem, disease, or poor management) has already weakened the hive.
- Cause
- Wax moth larvae (Galleria spp.)
- Strikes
- Weak colonies, stored comb
- Tell-tale sign
- Webbing & tunnels in comb
- Best defence
- Strong colonies + light, aired storage
Overview
Two related moths — the greater wax moth (Galleria mellonella) and the smaller lesser wax moth (Achroia grisella) — lay eggs in cracks and crevices of a hive. Their larvae then tunnel through beeswax comb, eating wax, pollen and the cocoon silk left behind by developing bees, and spin dense webbing as they go, which is the most recognisable sign of an infestation.
A strong, well-populated colony patrols and defends every part of its comb, removing wax moth eggs and larvae before they can establish, so wax moth is overwhelmingly a problem of weak colonies (queenless, disease-weakened, or simply small) and of stored spare comb that has no bees guarding it at all. It is best understood as an opportunist that moves in once a colony can no longer defend itself, rather than a disease that attacks a healthy one.
Left unchecked in stored equipment, wax moth larvae can reduce a full frame of drawn comb to a mass of webbing, frass and tunnels within a few weeks in warm weather, destroying comb that took the colony real time and resources to build — the practical cost is usually in ruined stored comb and frames, more than in hive losses from an infestation inside an active, strong colony.
This is a general guide, not a substitute for a veterinarian. Always call a vet for diagnosis, dosage and treatment of a sick animal.
Signs to look for
- Dense, silky webbing spun across the surface of the comb, often trailing frass (dark larval droppings).
- Visible tunnels chewed through the wax, sometimes lined with silk.
- Cream-coloured caterpillar-like larvae in and around the webbing, especially in the corners and edges of frames.
- A weakened, dwindling colony with patchy comb and reduced brood, or an outright abandoned hive with heavily webbed, ruined comb.
- In stored spare comb: a strong smell and visibly collapsed or hollowed-out cells even without opening the box.
Why it targets weak colonies and stored comb
- Bees constantly patrol and clean their comb; a strong colony physically removes wax moth eggs and young larvae before they can tunnel in, so healthy hives rarely have a real infestation.
- A queenless, diseased or otherwise weakened colony has too few bees to guard every frame, giving wax moth the opening it needs.
- Stored spare comb and frames have no bees on them at all, making them the single most vulnerable material on an apiary — this is where the worst damage usually happens.
- Warm, dark, still storage conditions are ideal for wax moth development; light and airflow slow it down considerably.
Protecting an active colony
- Keep colonies strong: a well-fed, well-managed, adequately sized colony is the single best wax moth prevention there is.
- Requeen promptly if a colony goes queenless or its queen is clearly failing, since a dwindling worker force is exactly when wax moth gets in.
- Reduce the hive entrance and internal space (fewer boxes) to match a genuinely small colony, so the bees can physically patrol and defend all of it.
- Remove and deal with any burr comb or debris on the hive floor, which gives wax moth an easy first foothold.
Protecting stored comb
- Store spare comb and frames in a lit, ventilated space rather than a dark, still, enclosed one — wax moth thrives in exactly the conditions of a sealed dark cupboard.
- Inspect stored comb periodically through the season and remove any frame showing early webbing before it spreads to the rest of the stack.
- Freezing drawn comb for 24–48 hours before storage kills any eggs or larvae already present, and is the most reliable single treatment for comb going into storage.
- Stack stored supers with airflow between them rather than sealed tightly together, and keep the storage area free of scraps of wax or propolis that could also attract moths.
- Give a heavily infested comb a thorough scrape and clean, or melt it down for wax, rather than trying to save it for reuse once tunnels and webbing are extensive.
Animals affected
Open an enterprise page for its full feeding, breed and vaccination-calendar guide.
Frequently asked questions
I found wax moth in my strongest hive. What went wrong?
A genuine infestation inside an otherwise strong, active colony is unusual — check first for a hidden underlying problem such as a failing or recently lost queen, disease, or a sudden drop in worker numbers, since wax moth typically only gets a foothold once a colony can no longer patrol every frame. Fixing that underlying issue matters more than treating the wax moth directly.
Can wax moth spread disease to my bees?
No — wax moth larvae eat wax, pollen and cocoon debris; they do not infect bees with a disease. The damage is entirely to the comb structure itself. That said, a heavy infestation is often found alongside a colony already weakened by something else, so it is worth checking for other problems rather than assuming wax moth is the only issue.
Is it safe to reuse comb after a light wax moth infestation?
Comb with only light, early webbing can usually be scraped clean, frozen for 24–48 hours to kill any remaining eggs or larvae, and reused. Comb with extensive tunnelling and heavy webbing has usually lost too much structure to be worth saving — melting it down for wax and starting the frame fresh is generally the better use of your time.
Does freezing comb before storage really work?
Yes — 24–48 hours at freezer temperature reliably kills wax moth eggs and larvae present in the comb at the time. It does not, however, protect comb from being reinfested later if it then goes into warm, dark, still storage for months, so freezing is best treated as the first step before proper light, ventilated storage, not a one-time fix on its own.
Signs, prevention and treatment follow ICAR, DAHD and state veterinary-university practice; vaccine schedules are the commonly notified ones and may vary by region or outbreak status. Always confirm with a veterinarian before treating an animal. editorial policy.