Beekeeping & Integrated Pest Management
Posted by on August 02, 2017
When people first approach beekeeping, they consider the positives: forging a human connection to nature, aiding in the pollination of your neighborhood and reaping the benefits of the products of the hive. And that is all true. Beekeeping is mostly a laissez-faire hobby, but we are beekeepers, not bee-havers. There is work involved. And if you choose to mindfully manage your bees, you will likely come across various degrees of invention to maintain bee health. Having an evolving Integrated Pest Management (IPM) strategy is the crux of beekeeping.
What is Integrated Pest Management in regards to Beekeeping?
Integrated Pest Management (IPM) is a multi-pronged approach for dealing with pests of the honeybee and beehive. An IPM strategy discourages reliance on a single, repeating approach; it involves timely monitoring and action. There are many methods of monitoring and depending on the results, various forms of action (or non-action!) to take.
Our Bee2Bee July Client Lesson covered the various methods of monitoring and a discussion of pest biology and treatments. We also discussed the non-treatment method.
Pests of the Houston Beehive
Here in Houston, honeybees face various pests (wax moths, ants, crazy ants, raccoons, possums, etc) but the main two I've seen devastate hives are Small Hive Beetles and Varroa Mites, which were the focus of our July lesson.
Small Hive Beetles
Small Hive Beetles, who thrive in hot and humid areas, are not-surprisingly pervasive in Houston. The black, sunflower-seed-shaped beetles are normally found on inner-covers and on the outside frames of the hive. Some people see them on the bottom of the hive as well. If you live in Houston and don't have Small Hive Beetles (SHB), you will soon; they are a fact of life and part of the ecology of the hive.
Life Cycle of SHB
Adult Small Hive Beetles may live up to 6 months and have 4–5 generations a year during the warmer seasons. Female beetles lay masses of eggs in cracks or crevices in a hive. In some cases, they even lay in the brood nest! The eggs hatch in 2–3 days into white-colored larvae that will grow to 10–11 mm in length. Larvae feed on pollen and honey (and in severe cases pupae), damaging combs, and require about 10–16 days to mature. Larvae that are ready to pupate leave the hive (usually dropping through a bottom screen) and burrow into soil near the hive. The pupation period lasts approximately 3–4 weeks. Newly emerged adults seek out hives and females generally mate and begin egg laying about a week after emergence. (source: Wikipedia & Bee Culture)
The Problem with SHB
The adults we normally see (and smash!) are not the issue. It's the feeding activity of the larvae that is the problem. Larvae tunnel through comb with stored honey or pollen, destroying it. Larvae defecate in honey and the honey becomes discolored from the feces. Activity of the larvae causes fermentation and a frothiness in the honey; the honey develops a characteristic odor of decaying oranges. Popularly called "sliming the hive," damage and fermentation cause honey to run out of combs, creating a mess in hives or extracting rooms. Heavy infestations cause bees to abscond; some beekeepers have reported the rapid collapse of even strong colonies. Sometimes the SHB infestation causes the bees to abscond, sometimes SHB take over once a hive has absconded for other reasons - it's often hard to tell on hives not well monitored. (source: Wikipedia)
IPM Strategy of SHB
The #1 strategy against the little black beetles: a strong colony. Bees are very good at controlling Small Hive Beetles. They are the ones that push them to the outside frames and to the innercover. You've probably witnessed them chasing down and corralling a SHB. They'll even build little jails out of propolis (which the beekeeper will inadvertently open). But, it is a numbers game. SHB can take over if the colony is weak or small.
Various strategies against Small Hive Beetles:
- Maintaining a full, strong colony (duh)
- Not giving the bees too much space - if they are a small colony, consider a nuc hive - if they are *almost* ready for another super but are having queen issues or have been losing the SHB battle, perhaps wait to add the next box
- Sunshine - SHB hate light - the shadier the beehive, the more SHB you'll have. I have no preference for full sun or full shade hives, but know you'll might need more precaution with shady hives
- Screened Bottom Boards vs Solid - this is a debatable subject - some say the screen helps the larvae drop to the soil and return. I personally employ a screened bottom board with a West trap underneath
- Physical Traps - there are many physical things that can help bees trap SHB. Cut up "Beetle BeeGone" sheets (unscented Swiffer or Swiffer generic sheets work just as well), Beetle Blaster traps, Beetle Barns, Freeman Beetle Trap and West Trap - the list goes on and on
- Ground Drench - If you want to go the chemical route, you can apply a drench to the soil around the hive, but it can be harmful to crawling bees.
- Nothing at all - Beekeeper Dean Cook of the Houston Natural Beekeepers Association says that when he stopped trying to fight Small Hive Beetles he suddenly stopped losing hives to Small Hive Beetles
Note: Bee2Bee did lose a hive to Small Hive Beetles earlier this summer. It was the result of a stalled nuc (the nuc came with supersedure cells); we received a new queen but the overall numbers of the workers remained low. I noticed that the female SHB were laying eggs in the inner frame feeder - if you see a lot of larvae in your feeders, you may want to switch to another method of feeding (or stop feeding altogether).
Bee2Bee strategy: depending on the hive and if SHB are present or not - a combination of Swiffer sheets, Beetle Blasters with food grade diatomaceous earth (DE), Beetle Barns with DE in top bar hives, and West traps with DE. In some cases - nothing at all.
We had previously employed vegetable oil in the traps - which was messy and turn rancid - then mineral oil in the traps - which was pricey and still messy - before switching to diatomaceous earth. Yes, diatomaceous earth is harmful to honeybees as well, which is why one needs to be careful when putting it in the trap. Steve Brackmann, the president of the Houston Beekeepers Association told me he has switched to using garden lime in his beetle blasters.
Varroa Mites are the biggest pest threat to honeybees. So much so that most bee conventions you go to focus more on the mites than the bees! Randy Oliver said at the recent Texas Beekeepers Association clinic that it's almost as if we are raising varroa mites, not raising bees. Mites are also a fact of life in the hive and the IPM strategy is ensuring that their numbers remain in check.
Life Cycle of the Varroa Mites
To simplify things, we'll concentrate on the female - there are two stages: the phoretic stage and the reproductive stage. The phoretic stage is when the mite rides on adult bees - they can hop from one bee to another and transmit diseases. The phoretic stage lasts about 5-11 days when there is brood in the colony.
The other stage is the reproductive stage, which occurs only under the capped brood cell. The varroa mite invades a host (worker or drone larvae) cell just prior the cell being capped. Once inside, she will hide in the brood food in an upside-down position (viewed from the top of the cell). The first egg is laid 70 hours after cell capping. The first egg is not fertilized, and becomes a male. After this, approximately every thirty hours, the mite lays a female egg. A total of five (on worker pupae) or six eggs (on drone pupae) can be laid in a capped cell. However, because worker bees will emerge about eleven days after capping, and drones fourteen days, but a daughter mite takes six days to mature, most of these eggs do not have time to develop into adults. The mites who are not fully developed, all die shortly due to dehydration after a cell is opened (after bee emergence, or uncapping by hygienic bees). Therefore only the mature, tanned female mites are seen by most beekeepers. Because of this phenomenon, varroa tend to prefer the larger drone brood (source: eXtenstion.org).
Monitoring for Mites
Bee colonies can tolerate a low number of mites, but will decline or die as mite numbers rise. Accurately assessing and understanding mite population is the basis of an IPM control strategy. Beekeepers can assess mite populations during any of the phases of bee/mite population cycles. Generally, a beekeeper should perform Varroa monitoring assessments at least four times during the year, beginning with the Population Increase phase. During the Population Decrease phase, mite levels should be re-checked to confirm that mite numbers are low going into the Dormant phase. During the Dormant phase, sampling should continue, if possible (source: Honey Bee Health Coalition).
Monitoring Methods for Varroa
There are many different ways that people monitor for varroa - at Bee2Bee, we give the option of two main ways (or, one can opt out if requested).
1. The Alcohol Wash - this involves shaking a frame of brood, collecting a half cup of bees (approximately 300 bees) and dunking them in alcohol.
Pros: considered the most accurate test, quick, not pricey
Cons: kills 300 bees, can accidentally kill queen if you are not careful
In previous years, Bee2Bee only used this test - complete with wire strainer and special viewing bowl. After attending the Texas Beekeepers Association Summer Clinic and seeing Randy Oliver's keynote - we are now employing the poor woman's version of the Mite Checkers sold on beekeeping websites: 2 plastic cups with a piece of tulle between
Pour the half cup of bees, swirl and voila - mites fall through the tulle to the bottom. Bonus: I'm using yellow tulle, because fashion.
You then count the mites, divide by 3 and have the percentage of mites in the hive.
You may also knock off pollen and other bee bits - but in the above test, two mites were found. They are quite visible - rust colored and round. If you have good eyes, you'll even see their appendages.
For those that fret about killing bees, please keep in mind that up to 1500 bees die every day in a full colony. As one of my clients Aida says, "they'll make more."
2. The Sugar Roll Method
Here is quite the same method: shake a frame of brood into a tray, collect a half cup and put them in a jar with a tulle lid. Add 2 tablespoons of powdered sugar and roll to cover the bees. Set aside for 2 minutes. Shake vigorously onto a white tray for 60 seconds. Dissolve the sugar with water and you should be able to count mites. Replace bees into the hive.
Pros: Easy, doesn't kill bees
Cons: Slightly more time consuming, slightly messier, less accurate
The University of Minnesota Bee Squad did a great video on this:
Note: to test Top Bar Hives, we simply brushed bees off of 1-2 brood frames and employed the same methodology as a Langstroth.
Treatment for Varroa
Depending on your testing - you may decide to treat (or not). We will discuss the pros and cons of various methods of treatment, including the natural treatment method, in August's lesson. Stay tuned!