Greater Wax Moth

Galleria mellonella — the greater wax moth — is one of the most familiar honey bee pest species in temperate beekeeping and (since 2017) one of the most-studied insects in plastic biodegradation research. The species' caterpillars feed on the wax comb of honey bee colonies — devastating weak or unattended hives by tunneling through and consuming the wax structure that forms the colony's brood and honey storage architecture. Strong active honey bee colonies usually keep wax moths in check by physical defense, but weakened colonies can be entirely destroyed within weeks. The species is one of the most-encountered destructive pests of beekeeping equipment storage. The species' more remarkable scientific significance was discovered accidentally in 2017 by Federica Bertocchini, a Spanish amateur beekeeper and developmental biologist who removed wax moth larvae from her hives and stored them in a plastic shopping bag — within hours she noticed holes appearing in the bag. Subsequent investigation (Bertocchini et al., Current Biology, 2017) confirmed that G. mellonella larvae can digest polyethylene at a rate of approximately 0.13 mg per hour per larva — approximately 40,000 times faster than environmental polyethylene degradation. The biochemistry is still being worked out: gut bacteria isolated from wax moth larvae degrade polyethylene in vitro, suggesting bacterial digestion; but recent work also suggests larval salivary enzymes may break the polymer chains directly. The species has therefore become one of the most-studied insects in plastic biodegradation research, with potential applications for plastic waste management.