Honey bees are generally peace-loving insects, focused on building out their hives and preparing for winter. But that doesn’t mean they don’t have to face a slew of threats in their short lives. In this article, we’ll look at the pests, predators, and diseases that bees are up against.
What are the honey bee’s main threats?
Honey bees are faced by many pests and parasitic threats including varroa mites, tracheal mites, and wax moths. Predators like bears, hornets, wasps, and ants are always on the lookout for honeycomb to steal. But the greatest threat to the honey bee is humans through the use of pesticides and urban expansion.
1. Varroa Mites
When it comes to parasites, the biggest threat to the honey bee is the varroa mite. This tiny creature is doing damage all over the world, feeding and reproducing on bee pupae and larva.
Mites transmit viruses through the colony, weakening and malforming developing honey bees. They also feed off the blood of adult bees, further impacting the colony. A problem that is compounded by drifting and robbing colonies who spread the pathogens further.
For beekeepers, varroa mites are difficult to eradicate. They’re versatile enough to live off adult bees or their brood. They also reproduce rapidly and can spread through colonies fast.
Varroa mites are a reddish-brown color and have 8 legs. They’re big enough to be seen by the human eye, but that doesn’t mean you’ll spot them. They often hide the honey bee’s abdomen or thorax segments.
To look for common symptoms of parasitic mite syndrome, search for signs of bee deformity or scattered brood that’s uncapped. Other giveaway signs are rapid population loss and unusual social behavior that’s lacking coordination.
The most effective way to mitigate varroa mites is the careful application of chemical sprays. Extreme care must be taken to avoid harming the bee population or contaminating their honey.
2. Tracheal mites
The tracheal mite, or Acarapis woodi, is a tiny mite that is found on every continent except Australia. It lives in the tracheal system of the adult honey bee, feeding off the insect’s blood.
These mites are a serious threat to the bee population, responsible for reducing the performance or killing off colonies.
They are microscopic so it’s impossible to detect them and there are few obvious symptoms. For an accurate diagnosis, lab testing by dissecting bees under the microscope is necessary.
A pack of menthol pellets is great for controlling tracheal mites. Place them in the infected hive on top of the frames and allow the vapors to kill the adult mites.
Grease patties made with 2 parts granulated sugar and 1 part vegetable shortening will also work. The bees try to eat the sugar and end up covered in grease, stopping the mite from spreading to other bees.
Recommended reading: what are tracheal mites?
3. Wax Moths
There are two wax moth species, the Lesser was moth (Achroia grisella) and Greater wax moth (Galleria mellonella). Both are parasites that cause issues for honey bees.
Wax moths affect bee colonies globally, eating beeswax, cocoon silk, pollen, bee feces, and larval remains. They often target weak or diseased colonies, causing damage to the hive’s honeycomb stores.
To reduce the onset of wax moths, beekeepers should keep colonies that have a high bee-to-comb ratio. Knowing when to add supers so that there is minimal unused space is crucial.
Other ways to defend against these moths is to keep the hive free from propolis, burr comb, unattended comb, and brood that’s over 3 years old. Keep well-maintained frames that don’t have any splits or gaps for the moth to get established in.
4. Tropilaelaps mites
The tropilaelaps mite is a parasite that reproduces on brood and feeds off drone and worker bee blood. They are a nasty variety of mite, often more serious than the Varroa destructor.
An infestation of these mites can cause severe damage to a bee colony. Parasitic mite syndrome, damaged and stunted appendages and colony decline are all symptoms of this pest. They also spread viruses through colonies when the bees abscond or swarm. Read more about bee swarms here.
If you suspect tropilaelaps mite in your beehives, look for signs of weak or stunted bees with smaller than average abdomens. You’ll probably see bees crawling near the entrance, unable to take off into the air. An inspection of the hive will reveal dead, irregular brood and a lot of hollow cells.
Removing tropilaelaps mites from a beehive can be a headache. Chemicals will work, but keeping within recommended doses is crucial to the survival of the colony. During heavy pollen flow, you can also starve the mites by temporarily removing the sealed and unsealed comb frames.
Learn more about Tropilaelaps mites here.
5. Small hive beetle
Small hive beetles, or Aethina tumida, are small blackish-brown insects with clubbed antennae. They originated from sub-Saharan Africa and are fairly harmless in that part of the world. However, since arriving in countries like Australia and the United States, the pest has wreaked havoc on honey bee colonies.
The beetle burrows into the comb of active hives, eating the honey, pollen, and brood. The beetle’s larvae carry a yeast species (Kodamaea ohmeri) that contaminate honey and make it ferment. Too many of these beetles will cause the colony to abscond or die out.
Beekeepers will find it difficult to detect small hive beetle in small numbers. Once established, you’ll see signs of the adult beetle or their eggs and larvae. You may notice hive damage or greasy, slimy honey that weeps from the comb cells. Another tell-tale sign is a rotting orange odor.
There is a range of mechanical traps designed to eradicate the small hive beetle population. They usually have a small opening that allows beetles to enter, but not bees. Inside the trap, there is a mineral or vegetable oil that drowns the pest.
There is a range of arthropods, both small and large that use beehives as shelter. Insects like spiders, earwigs, and cockroaches are considered pests. Although they don’t harm the bees, they provide no benefit either.
Management of these pests is relatively simple. Beekeepers should clean up the affected areas as well as keep any equipment well maintained and clean.
7. Braula fly
The braula fly (Braula coeca) is a small wingless fly that is widespread across all continents. It is considered a minor pest to the honey bee. The braula larvae damage the honeycomb wax cappings, while the adults steal food in small quantities.
You can easily observe damage caused by braula fly larvae. Narrow tunnels under the wax cappings can be seen from the surface. The comb will have a cracked appearance, making it less marketable when it comes to selling.
In most cases, beekeepers don’t need to control this pest as it doesn’t cause harm to the bee colony. If you’re specializing in producing honeycomb for sale, then freeze the combs for 48 hours to kill the braula fly at all stages of its lifecycle.
Learn more about the braula fly appearance, symptoms, treatment, and latest research here.
8. Black Bear
In parts of North America, black bears are notorious predators of honey bees. The bear will often accept bee stings in return for stealing the colonies honeycomb. In the process, bees will also die.
Beekeepers will often erect electric fences to ward off unwanted bears. The system could be as simple as two wires, but there are some more elaborate defense systems on offer. If you chose to use an electric fence, be sure to set it up before the bees are introduced.
Find out how to keep bears out of hives here.
Raccoons are capable of seriously damaging a beehive. They feed on honey and bee brood, a lot like bears do. Raccoons can damage beehives by knocking them over and ripping out the frames.
If you discover hives sprawled over the ground, then raccoons may be the culprit. To protect against them, fill a piece of plywood with nails and use it as a deterrent at the front of the hive. You may also want to add stakes on each side of the hive for extra support.
Learn more: Do raccoons eat bees?
Frogs and toads aren’t a widespread issue for beekeepers, but in sufficient numbers, they can be a real problem for weak colonies. Amphibians will happily feed on honey bees at night, so be vigilant for droppings around the hive.
To deter toads and frogs, spray all the areas around the hive with vinegar. This acts as an excellent deterrent. You may also want to remove wet areas and erect physical barriers to keep your hives safe.
Birds aren’t a major problem for beekeepers as most varieties will only eat an injured or dying bee on the ground. Some birds specialize in catching bees, like the summer tanager and bee-eater. Other species include swifts, thrushes, mockingbirds, martins, and kingbirds. Woodpeckers enjoy bee larvae when it’s on offer.
To ward off birds, you can use a scarecrow. In most cases though, birds aren’t a big concern for bee colonies.
12. Hornets and wasps
In most parts of the world, hornets and wasps will target weak bee colonies. They often attack foragers outside of the hive, but they’re also known to enter the hive.
Giant Asian hornets are a relatively new threat to honey bees. Yellow jacket wasps can also be a problem if they have the numbers. Find out the difference between yellow jackets and honey bees here.
The genus Vespula is an aggressive wasp that invades hives, killing the bees then stealing their honey and brood.
Beekeepers may reduce the hive entrance or set bait traps near the opening for wasps if they’re endangering the hive. Another option is to follow a wasp to its nest and kill the entire nest.
The commonest threat to honey bees is ants, which are an ominous threat to a weak colony. During an invasion, ants will take honey, brood, and bees (dead or alive).
If a beehive is overrun by ants, it’ll often abandon the hive and search for a new home. Beekeepers can reduce the chance of colony loss by searching for and destroying the invaders’ nests. Another useful defense is placing hives on support posts that are covered in a deterrent like oil or grease.
To learn more, check out 13 ways to keep ants out of beehives.
Without question, the honey bee’s biggest threat is the human race. The use of pesticides in our gardens and large-scale commercial farms contaminates the pollen. This issue alone is responsible for bees dying in mass numbers.
Another way humans contribute to the bee’s demise is urban expansion leading to loss of habitat. Climate change is resulting in dryer, hotter conditions that bee colonies are struggling to adapt to.
On a smaller scale, people are known to burn or destroy hives out of fear, rather than having them relocated. Honeycomb theft is also on the rise as honey prices edge higher.
15. Brood diseases
There are a range of brood diseases that range in severity for honey bees.
Foulbrood disease mostly affects honey bee larvae.
- European Foulbrood is more common and will usually fix itself with decent weather for foraging.
- American Foulbrood is much worse and can result in the death of larvae and capped pupae. There is no reliable cure and the spores can continue living for many years, waiting for a new hive to devastate. You can check the symptoms of American foulbrood here.
16. Nosema disease
Nosema disease affects honey bees. In cooler weather when food resources are scarce, it can cause significant losses for adult bees. Spores of microsporidian result in reduced honey and brood production, bee dysentery, and population decline.
To manage this disease, beekeepers should maintain strong colonies and make sure there is sufficient food. Comb rotation every 3-4 years and utilizing young queen bees will also reduce the likelihood of this disease breaking out.
A mouse can cause major disruptions to vulnerable winter hives. It can damage frames and comb making its nest.
Mice also feed on pollen, comb, and honey. This parasitic behavior is a big setback for honey bees when foraging isn’t an option.
Learn more about how to keep mice out of the hive here.