Honeybee Diseases, Parasites, and Predators Every Beekeeper Should Know

This is the chapter nobody wants to read but everybody needs to. Your bees have enemies. A lot of them.

Chapter 10 of Backyard Farming: Keeping Honey Bees by Kim Pezza covers the diseases, parasites, and predators that can threaten your hive. It is a big chapter, and for good reason. Knowing what to look for and how to respond can be the difference between a thriving colony and a dead one.

Robber Bees

Before we get to the scary stuff, let’s talk about robber bees. These are not a separate species. They are regular honeybees from other hives that come to steal your colony’s honey stores.

This usually happens during hard times when food is scarce. A scout bee from another hive finds a weak spot in your colony’s defenses, goes back home, and returns with reinforcements. A serious robbing event can completely wipe out a hive’s honey reserves, kill the queen, and destroy the colony.

Robber bees also spread diseases between hives, which makes the problem even worse.

Prevention: Keep your hive entrance small so it is easier for your bees to defend. Maintain a strong, healthy colony. Make sure your bees have enough food so they are not vulnerable targets.

Parasites

This is where things get serious.

Varroa Mites

If you keep bees long enough, you will deal with varroa mites. They are the single biggest threat to honeybee colonies worldwide.

Varroa mites feed on the body fluids of bees at every life stage. You can see them as red or brown spots on the bees’ bodies. Infested bees often develop deformed wings and shortened lifespans. A heavy varroa infestation can eliminate an entire colony. Some researchers believe varroa mites may also contribute to colony collapse disorder.

Treatment options:

• Chemical: Formic acid, oxalic acid, fluvalinate, or thymol-based treatments
• Mechanical: Drone-brood sacrifice (varroa prefer drone cells, so you remove drone frames to trap mites), powdered sugar dusting (makes mites lose grip and fall off bees), and screen bottom boards (mites fall through and cannot climb back up)

Most beekeepers use a combination of methods. There is no single silver bullet for varroa.

Acarine (Tracheal) Mites

These mites infest the airways of bees and transfer to younger bees through close contact. They are harder to detect than varroa because they live inside the bee’s body.

Tracheal mites nearly wiped out the entire British bee population in the early 1900s. That crisis directly led to Brother Adam at Buckfast Abbey developing the Buckfast bee, a strain bred specifically for resistance to tracheal mites.

Treatment: Grease patties made from vegetable shortening and powdered sugar. The grease disrupts the mites’ ability to transfer between bees.

Wax Moths

Wax moths feed on honeycomb wax and kill bee larvae in the process. They thrive in temperatures above 90 degrees Fahrenheit.

The good news is that a strong, healthy hive can usually handle wax moths on its own. The bees remove them. Weak hives are the ones that get overrun.

If you have frames in storage that get infested, you can kill wax moths by freezing the frames.

Small Hive Beetles

Small hive beetles are scavengers that target weak hives. They tunnel through the combs and contaminate the honey, making it unusable.

Control methods: Trap the beetle larvae, introduce soil nematodes around the hive (they eat beetle larvae in the ground), and maintain good hive cleanliness.

Fungal Diseases

Nosema

Nosema is an intestinal fungus that affects adult bees. There are two species: Nosema ceranae and Nosema apis. Infected bees have shortened lifespans and reduced ability to fly and forage.

Treatment: Fumagilen B is the standard medication. Good hive ventilation and keeping the hive clean also help prevent outbreaks.

Chalk Brood

Chalk brood is a fungus that infests the gut of bee larvae, essentially starving them to death. You can identify it by the chalky white mummified larvae in the cells.

The good news is that chalk brood rarely kills a colony. It tends to come and go.

Treatment: Increase ventilation in the hive. In persistent cases, re-queen the colony with more resistant stock.

Bacterial Diseases

American Foul Brood

This is the most widespread and destructive bacterial disease in honeybees. It affects young larvae and is caused by a spore-forming bacterium, which means the spores can survive in equipment and comb for decades.

American foul brood is serious. In many areas, beekeepers are legally required to report it.

Treatment: The shook-swarm method, where you transfer the adult bees to new clean equipment with fresh foundation and destroy the contaminated comb and frames.

European Foul Brood

Less deadly than American foul brood, European foul brood is often stress-related. It tends to show up in colonies that are weakened by other factors.

Treatment: The shook-swarm method works here too. Strengthening the colony and reducing stress factors helps prevent it.

Stone Brood

Stone brood is caused by the Aspergillus fungus and is thankfully rare. It hardens the larvae, turning them into stone-like mummies. One concerning note from the book: this fungus can also affect humans, so handle suspected cases with care.

Treatment: Increase ventilation and re-queen the colony.

Predators

Your bees face threats from the animal kingdom too.

Wasps and Hornets

Wasps and hornets are natural predators of honeybees. They raid hives for both honey and bee larvae. A strong colony can usually defend itself, but weak hives are vulnerable.

Ants

In tropical areas, ants can be a serious problem and can destroy entire colonies. In temperate climates, they are more of a nuisance than a threat.

Frogs, Toads, and Lizards

These are minor predators. They sit near the hive entrance and pick off bees one by one. You can reduce this by removing standing boards or anything that gives them a place to sit.

Bears

Bears are a real threat if you live near wooded areas. Interestingly, they are not going after the honey. They want the protein-rich pupae and larvae inside the comb.

Prevention: Keep your hives away from the edge of woods. Electric fencing around the apiary is the most effective deterrent.

Skunks

Do not underestimate skunks. They can destroy a hive in just a few nights. Their method is clever and annoying. They scratch at the hive entrance to lure guard bees out, then eat them.

Prevention: Chicken wire fencing around the hive, sunk 8 to 12 inches into the ground so they cannot dig under it.

The Big Takeaway

This chapter is a lot to take in. But the theme running through all of it is the same: keep your colonies strong and healthy. Strong hives can fight off robber bees, resist wax moths, and defend against most predators. Weak hives are sitting targets for everything on this list.

Regular inspections, good ventilation, adequate food stores, and prompt treatment when you spot a problem. That is the formula. There is no shortcut.

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