Predators and Pests

While I wouldn’t say I am perfectly comfortable tending a hive, I am getting more comfortable and confident that I can identify an issue if I come across one. Varroa mites are only one of those issues. We know that mites significantly reduce the health of a population and more so at this time of year when the colony is rearing its winter bees – those that must be strong enough to survive the winter. I have heard more than once this week that if your mites aren’t under control, your hives will die this winter.

The thing is, as much as we have worked to keep our mite populations under control this year, there are OTHER pests and predators that can still damage hive health. These pests range from very large to microscopic.

If we work from largest to smallest, animals such as bears tend to terrorize hives during the summer. One of our beekeeping friends right here in northern Midland County had a bear decimate his hive (again!). These bears are looking to eat not just honey but larval bees. There is not a whole lot that can be done to keep bears out of bee hives – but properly installed electric fencing can be effective. Unfortunately for our friend, his electric fence was damaged leaving an opportunity for the bear to invade.

Another animal that can wreak havoc on hives are skunks who are looking to make a meal out of the actual bees. Prevention includes elevating the hives to force the skunk to expose their belly to possible bee stings. They hunt at night when you won’t see them.

Mice are particularly dangerous in the winter months when the bees must cluster close together to stay warm, leaving areas of the hive unguarded. Mice will take up residence in the hive and make a nest in this nice shelter while decimating the honeycomb. The key to keeping out mice is to limit the hive entrance to a space so small that a mouse cannot get in but the bees can come and go.

Winter mouse guards at Dow Gardens (1/4 in hardware cloth)

There are insects that can cause problems for a hive and equipment. One that I was particularly worried about of late was wax moths. There are two species of wax moth, the Greater wax moth and the Lesser wax moth. Wax moths lay their eggs in the comb and when the larva hatch out, they eat their way through the beeswax eating the wax, pollen, remains of larval honey bees and other nutrient rich left behinds. They can also damage wooden frame and hive equipment by making cavities in the wood for cocoons. When I went into my personal hive the other week, I cracked open the inner cover and out flew a moth. It landed on the outside of the hive so I got a good look and it was a Lesser wax moth. YIKES!! I didn’t have time to delve deep that day into my hives so I had to stay concerned for the week until I could get back in there. I had heard of wax moths, but didn’t know much about them…so off to research I went. Turns out, wax moths are much more of a concern in unattended combs (like the stack of unused honey supers in my back yard) than in an active hive. In a strong, active hive, the bees can keep moth populations at bay. The good news: my hives don’t have a wax moth problem. The bad news: my stack of supers does!

Greater Wax Moth webbing on stored equipment

Preventing a wax moth infestation involves freezing equipment prior to storage and/or using moth crystals inside a tightly stacked group of unused equipment. This kills any moths, eggs or larvae before they can do damage. This treated equipment MUST air out for a while before being applied to a hive with bees. After an infestation has occurred, treatment is freezing the equipment. I don’t have a freezer large enough to put my equipment in, so I went through the frames, removed the larvae and treated the stack with moth crystals. Hoping this will keep the population at bay until freezing temperatures come – I am not in a rush for winter though.

Evidence of Lesser Wax moth infestation

The final pest I want to discuss is the small hive beetle (SHB). This is one I have not had personal experience with (yet). With the wax moth, the larvae are the stage that do the damage to a hive/equipment. SHB, on the other hand, both the adult and larva are detrimental to a hive. Again, a strong hive can typically keep SHB under control. It is when the beetles begin to match numbers with the worker bees or the hive has other factors that impact bee health, that the hive beetles can effectively prey on the honeybee eggs and brood. The larvae tunnel through honeycomb causing damage and destruction of the honey and leaving behind a slimy residue. The adult beetles defecate in the honey, introducing yeast which causes fermentation. This ruined honey is not fit for consumption for humans or bees and runs out of the comb leaving a characteristic odor like decaying oranges (note, scents are subjective). A veteran beekeeper told me that while wax moths can do a lot of damage, he finds SHB to be one of the grossest things possible – that is saying something because he (Dan Keane) has seen A LOT!

Detection of the hive beetle is rather easy once you know what you are looking for, especially if the infestation is severe. An attentive beekeeper will notice adult beetles running along the underside of the covers or the tops of the frames upon opening the hive. The adults and young larvae are drawn to dark locations in the hive whereas the older larvae are drawn to light. Knowing the habits of each stage of a pest species can help a beekeeper prevent infestations and/or deal with them before the issue gets out of control. There are many traps that can be purchased or constructed to detect or trap and remove SHB from a hive. Prevention of the hive beetle starts with placement of the hives in a sunny location as well as keeping a clean hive for good bee health.  

Finally, there are microscopic threats to bee colony that may be less easily detected but with careful attention during inspection, a beekeeper can notice something is off about the colony. Some of the microscopic pests and pathogens include: Bee viruses, Nosemosis, American Foulbrood (AFB), European Foulbrood (EFB), Amebiosis, Chalkbrood and Stonebrood and of course the Varroa mite. I won’t delve into these particular diseases, but it is good to research them and understand the issues they may cause in your colonies so that you are more likely to catch when something (invisible) is impacting your bees.

A good take away from my journey to discover pests and predators of honeybee hives is that the condition of your apiary is extremely important. Some of the following are good practices and things to know:

  • Keeping a healthy colony can keep your bees better able to defend their home; all hives have eggs from these (insect) pests at one time or another
  • Placement (sun exposure and elevation) of your hives
  • Keep vegetation down around the hives
  • Not tossing burr comb on the ground
  • Reducing entrances that bees have to defend from invaders
  • Clean hive equipment that is in good condition
  • Testing for pests frequently to detect problems early
  • Sanitary practices (clean hive tools, gloves, etc) to avoid the spreading of invisible pests and pathogens