Several pests can cause trouble for your honey bees, but two of the most common are small hive beetles and wax moths.
Both are a real nuisance. And they can be tricky to identify if you come across them for the first time. But each has distinct characteristics that will help you tell them apart.
Understanding these differences and pinpointing the problem is essential to helping your bees rid themselves of these pesky critters!
Small hive beetle larvae vs. wax moth larvae
Small hive beetles and wax moths can both be present in a hive simultaneously.
Or you can have just one or the other.
Most of the time, bees in a healthy colony can handle moth infestations themselves. They’ll expel the moth larvae and do all they can to prevent them from developing.
But wax moths are more likely to appear in a weak colony that has difficulty patrolling all the corners of the hive. If left uncontrolled, wax moths can destroy the brood comb and eventually cause the colony’s demise.
The moth larvae burrow tunnels through the wax comb, feeding on the wax, hive debris, and the cocoons and skins of bee larvae. They leave behind them a web of silk-like trails. (The larvae are far more destructive than the adult moths).
On the other hand, small hive beetles can be a problem even in a healthy hive.
This pest originates from Africa, so European bees (those raised by most beekeepers worldwide) do not have the natural instincts to defend themselves against the beetles.
Hive beetles will destroy the wax comb but also eat bee brood. As a result, they can quickly devastate a colony if the infestation gets out of hand.
The beetle larvae tunnel through the comb and eat pollen and honey, leaving a horrible slime in their wake (they do not leave webbing like wax moths). This slime is a deterrent to bees, so they won’t go near the beetle larvae when cleaning up around the hive. In addition, the honey in the damaged honeycomb slowly ferments, creating a sour smell.
If a colony is overcome by a small hive beetle infestation, the bees will abscond, leaving the hive in a mess. Of course, the beetles will eventually go as well, but only after consuming anything left worth eating!
Note: both wax moths and small hive beetles can be present in equipment stored for winter, such as supers and frames of comb. Be careful to check this equipment in the off-season. This way, you won’t re-introduce a problem the next time they are used in an active hive.
Differences between Small hive beetles and Wax moths
Small hive beetle larvae are smaller than wax moth larvae. But they can be confused with young wax moth larvae. They also have three pairs of prolegs near the head instead of several legs found on wax moth larvae.
It’s easy to confuse the larvae of hive beetles with those of the wax moth. The difference between small hive beetles and wax moth larvae is subtle. But there are a few features that can help you identify them.
What do small hive beetle larvae & eggs look like?
Hive beetle larvae are white or cream-colored grubs. They have three pairs of pretty large legs near the head (called prolegs). They also have many stubby spikes along their backs.
Small hive beetles lay eggs in uneven patterns around the hive and the comb. When inspecting for the presence of hive beetles, you would see small pearl-like white eggs in the nooks and crevices of the brood box and on brood combs.
Note that small hive beetle larvae have a hard exterior shell that is pretty difficult to penetrate. Try squishing one, and you’ll find it more difficult than crushing wax moth larvae!
How big are small hive beetle larvae?
The larvae of the hive beetles measure about 7/16 of an inch (11mm) long and about 1/16th of an inch (1.6mm) wide when fully grown. They can resemble young wax moth larvae at this stage, but they will never reach the same size as adult moth larvae.
What do hive beetles look like?
Small hive beetles (Aethina tumida) are very dark brown in color (almost black). The adult beetles have flat, round bodies that are about 7/32 of an inch (5.7 mm) long and 1/8th of an inch wide (3.2 mm).
These tiny critters are surprisingly fast!
During infestations, you can see them scurrying away when you lift the top off a hive.
What do wax moth larvae & eggs look like?
There are two varieties of wax moths. The Greater Wax Moth (Galleria mellonella) and the Lesser Wax Moth (Achroia grisella).
Lesser wax moth larvae are yellowish in color with darker brownish heads. The greater moth larvae start pinkish-white and get darker. Again they have a brown heads.
Their eggs are pinkish in color.
Wax moths will carve cavities on the woodwork inside your beehive to lay their young.
What’s the size of a wax moth larvae?
The size of the greater moth larva is about 3/4 of an inch (20 mm) long, compared to the lesser larva, which is about 25/64 of an inch (10 mm). The greater variety is the biggest problem because they cause more damage.
What does a wax moth look like
Wax moths are light gray-brown in appearance and look slightly mottled. Most of the time, you will see them running around with closed wings. The adult moth measures about 20mm long (¾ inch).
Table of Comparison between Small hive beetle and Wax moth larvae:
Small hive beetle larvae:
Wax moth larvae:
3 pairs of prolegs near the head. They are larger than the legs of wax moth larvae.
Many legs along the length of its body.
Stubby spines along their back.
Smooth backs with a few thin hairs.
Cream-white in color.
The Greater variety is pink-white in color. The Lesser variety is yellow-white. Both have brown heads.
Hard exterior bodies (difficult to squash).
Soft bodies (easy to squash).
Do not spin webs, but develop into pupae at the bottom of the hive.
Leave web like trails in the comb.
How do you know if you have a small hive beetle infestation?
If you find larvae in the brood chamber, the easiest way to identify them is by their most distinguishing features. Hive beetles have a set of three prolegs and spines along their back. The larvae will usually be accompanied by the presence of adult beetles.
Look for beetles in the bottom corners of the brood box. Small hive beetles prefer the dark, so they hide away in the crevices of the hive.
If a small hive beetle infestation has been developing for a while, you may also notice a sour, yeast-like smell. This comes from the damaged and abandoned fermenting honey cells.
How do you know if you have wax moths?
Keep in mind that wax moths are primarily active in warm weather. And in fact, they tend to be easier to control in cooler northern climates.
The presence of adult moths is an obvious giveaway if you have a hive invasion. Wax moths do not like light (they tend to fly at night). Therefore, if moths are present inside your hive, you will see them scattering away into the dark corners when you lift off the lid.
The brood comb can become covered with silky webbing left by the tunneling larvae. This is a noticeable difference with small hive beetles, which do not leave webs.
Sometimes the larvae chew the cappings off sealed brood and expose the bee pupa. This problem is called ‘bald brood’ and can clearly indicate the presence of wax moths in significant numbers.
If the only signs of wax moths are the larvae, check their physical appearance and compare them with hive beetle larvae. Remember, if it has many legs and a smooth back, it is probably a wax moth larva, not a hive beetle.
If your colony is strong, the bees can control the wax moths, but it is always worth killing any larvae you see roaming around inside the hive.
Wax moths are thought to cause $5 million in damages to apiaries in the US alone! And hive beetles can cause so much damage that bees are forced to abandon the hive.
Good beekeeping management is the simplest way of keeping track of these pests. Keep the hive’s interior clean and free of burr comb, and clean out the corners and joints of the hive.
Oh… and be careful when storing hive equipment to ensure it’s free from pests.