There are two species of wax moth that cause damage to honeybee colonies by consuming beeswax as their larvae develop and in the process of making a pupal cocoon, they score the wooden frames that hold the wax combs, weakening the wood. Damage becomes obvious as they produce large quantities of grey-white webbing and dark faecal material as they feed. The larger of the two species (3/4 inch long grey-brown adult), the greater wax moth, Gallaria melonella causes more damage and has a wider distribution while the lesser wax moth, Achroia grisella is more limited to warmer southern states. Wax moths are not a cause of colony death, they come in later after some other factor/malady has reduced the population of honeybees. Strong colonies of honeybees with large worker population can reduce numbers of wax moth to a level where they cause little damage. – John Skinner, University of Tennessee