Wax moth can be a serious pest for bees , both for honeybees and bumblebees. There are two species in the UK. The lesser wax moth ; Achroia grisella and the Greater Wax moth ; Galleria mellorella. The adults do not represent a problem, as they only feed on liquids, nectar and pollen but their larval stage can be deadly to bee colonies, especially bumblebee colonies.
Adult moths can fly at lower temperatures than bees and mate and lay eggs at night. Tests with pheromone traps to catch and trap adults have not been successful so far. The Wax moth often lay their eggs on the outside of the Bee colony such as the exterior of Beepol Bumblebee Villas or if they can get access, on the outside of the cardboard container inside the Beepol Villa. In warmer temperatures these eggs will hatch within a few days. In cooler temperatures they develop much more slowly but tend still to develop , even if it takes several months. They hatch into small larvae, which are highly mobile and capable of crawling through very small spaces.
.Once the larvae get access to the Bee brood , the damage is often fatal. The larvae burrow into bee cells destroying them and the young bee larvae inside. They also secrete a sticky substance, which often traps and seals in the bee larvae, preventing them from emerging. They also create "spider like" webbing inside the colony, which the adult bees are not able to remove. The Wax moth larvae are very small to start off with but develop into quite large grubs, they are often a white to green in colour and can appear in large numbers.
How to control and prevent wax moth damage
If you already have an existing Beepol Villa that you wish to re-populate with a new Bumblebee colony, make sure it is free of wax moth pupae, eggs or larvae before you place the colony inside. The Wax moth larvae often burrow into the wood surface , so they must be removed with a wire brush and or by washing the inside of the Beepol Villa with warm water and fairy liquid. Once you have inserted your new Beepol colony in the Villa, monitor it on a regular basis for Wax moth larvae. They normally appear from June onwards but it can be earlier in a warm spring. Often, the larvae will first be seen on the inside of the Villa but on the outside of the Bumblebee colony, these should be removed if possible or treated with Wax moth Killer nematodes, which should be sprayed directly onto them but not inside the colony. The nematodes kill the wax moth grubs but do not harm the bees.
See Wax Moth Killer for more details.