The greater wax moth, Galleria mellonella, poses a significant threat to bee colonies and stored beeswax. The adult female moth does not feed, but she seeks a protected place to deposit her eggs, which initiate the destructive process. Identifying these tiny eggs is the initial, and often most difficult, step in preventing extensive damage.
Physical Description of the Eggs
Wax moth eggs are remarkably small, making them nearly invisible to the casual observer. They are typically oval or spherical, measuring less than half a millimeter in diameter (around 0.5 mm). This minuscule size allows the female to tuck them into narrow, protected spaces.
The color of the eggs changes slightly over time. When freshly laid, the eggs appear creamy or pearly white, sometimes having a slight pink tint. As the eggs develop and near hatching, they may turn a pale yellowish color.
Females lay their eggs in clusters or batches, often ranging from 50 to 150 eggs at a time. These masses of tiny, pale specks are usually glued together. This clustering can make them slightly easier to spot in a protected crevice.
Common Egg Laying Locations
The adult female moth seeks dark, protected environments to lay her eggs, hiding them from the defensive bees in an active colony. Primary locations to inspect are the cracks and crevices within the wooden components of the hive body or stored equipment. These narrow spaces offer necessary shelter for the delicate eggs.
Moths deposit egg masses between frames, along the joints of the hive box, and in any small gap they can access. They prefer areas that are dark and inaccessible to the honeybees’ cleaning and defensive efforts. When infesting stored equipment, eggs may be found in the external cracks and joints of stacked boxes, allowing larvae to tunnel in after hatching.
The female is particularly drawn to old, dark brood comb, as this wax contains the larval skins, pollen, and debris that the emerging wax worms prefer to feed on. Although less common, eggs can sometimes be found directly on the surface of this dark comb, especially in a weak or unattended hive. A thorough inspection requires close examination of the entire structure, not just the comb itself.
The Importance of Early Identification
Finding the eggs before they hatch is the most effective point of intervention. The incubation period is relatively brief, lasting only a few days to a few weeks, with warmer temperatures accelerating the process. At optimal temperatures, ranging from 84°F to 95°F (29°C to 35°C), eggs can hatch in as little as three to five days.
Once the tiny larvae, or wax worms, emerge, they immediately begin to burrow through the beeswax comb. Larvae consume the wax, stored pollen, and cast-off skins of bee pupae, causing significant damage. They line their tunnels with characteristic silken webbing and leave behind dark fecal matter called frass, creating a destructive trail.
If the egg stage is missed, the growing larvae can destroy an average of 100 cells of beeswax comb per larva. As the infestation progresses, the silk webbing restricts the movement of bees and can cause galleriasis, where emerging bees become entangled and die. Early identification is crucial to preventing this rapid destruction of valuable comb and equipment.