Friday, September 18, 2015

Oxalic Acid FAQs

Oxalic Acid is a naturally occurring acid found in plants. It became popular in Europe & Canada for treating Varroa Mites in a honey bee hive.

Oxalic Acid has been approved by the EPA to treat honey bee colonies in the United States. It must pass state approval before it may legally be sold in each state. This is a continuing process and a list of states that have been approved can be found on our website.

Versions of Oxalic Acid can be found in hardware stores but those have various additives mixed with them that can cause issue with the bees. Also it is illegal to use them for hives.

The most effective time to treat a hive with Oxalic Acid is when a hive has little to no sealed brood. It cannot penetrate capped brood so it will have no effect on the next generation of mites that were left in capped brood. You can treat in the spring and summer but research shows that Oxalic works best in the fall/winter.

The best time for a broodless hive is during late fall through the winter. You can also manipulate the hive by caging the queen for 14 days. That keeps her from laying and capping any more brood. 14 days provides enough time to treat your hive and allow the treatment residue to subside before returning the queen to lay brood.

While some studies say you can treat honey bees in the summer, there are too many variables that can cause issues during summer treatments. Summertime is usually when the hive is full of capped brood so it could take multiple treatments to reduce all the mites concealed with the brood. Continuous multiple treatments can affect the bees severely.

It has not been approved for use during a honey flow. If you have honey supers on the hive you must remove them before treating and leave them off for at least 14 days to give the Oxalic Acid treatment time to be fully cleansed from the hive to avoid contamination of the honey.

There are three approved methods to treat with Oxalic Acid:

Solution Method:
Note: To completely dissolve Oxalic Acid Dihydrate, use warm syrup.
Dissolve 35g of Oxalic Acid Dihydrate in 1 liter of 1:1 sugar water (weight : volume). Smoke bees down from the top bars. With a syringe or an applicator, trickle 5 ml of this solution directly onto the bees in each occupied bee space in each brood box. The maximum does is 50ml per colony whether bees are in NUCs, single, or multiple brood chambers.

Under certain unfavorable conditions (e.g. weak colonies, unfavorable overwintering conditions), this application method may cause some bee mortality or overwintering bee loss.

A complete kit is available with all the parts you will need for Solution Method (35 grams Oxalic Acid, nitrile gloves, protective goggles, 60mm syringe, and instructions)

Vaporizer Method:
Apply only to outdoor colonies with a restricted lower hive entrance. Seal all upper hive entrances and cracks with tape to avoid escape of Oxalic Acid vapor. Smoke bees up from the bottom board. Place 1g Oxalic Acid Dihydrate powder into vaporizer. Follow the vaporizer manufacturer’s directions for use. Insert the vaporizer apparatus through the bottom entrance. Apply heat until all Oxalic Acid has sublimated.

Spraying Package Method:
Ensure bees are clustered before applying.
Spray broodless package with 1:1 sugar water solution (without Oxalic Acid mixed) at least 2 hours before spraying with Oxalic. This fills their stomachs to reduce ingestion of Oxalic Solution.
Mix 1:1 ratio sugar water with 35 grams of Oxalic Acid (same ratio as Solution Method). For a 2 lb package, use 21mL of solution. For a 3 lb package use 31mL solution.
Store bees in a cool darkened room for 72 hours before hiving.

*All totals calculated from dosage amounts listed in treatment methods above.
Solution Method: 20 hives
Vaporizer Method: 35 hives
Spraying Package Method: 47 2lb packages & 30 3lb packages

DO NOT let Oxalic Acid make contact with skin, eyes, or be ingested. Wear proper personal protective equipment (rubber gloves, safety goggles, long sleeve shirt) when mixing or distributing Oxalic Acid. If exposure to skin or eyes does occur consult directions and safety sheet for instructions. If severe reaction occurs, call 911. Wash hands, exposed skin, and PPE directly after treatment to avoid contamination.

The effectiveness of Oxalic Acid treatment can be in excess of 95%, but solution method have a higher efficacy.

You will only want to treat your hive ONCE during the fall/winter. Honey bees have a low tolerance to Oxalic Acid.  Overexposure can cause issues and death in the hive.

As with any other treatment, some bee mortality may occur, especially if hive is already weak. Check your mite count and strength of hive before applying any treatment. If you are uncertain of hive’s strength, you can get a second opinion by asking a local beekeeper or your local bee inspector.

Since it is a naturally occurring chemical, it can be used in conjunction with other non-varroa treatments. DO NOT mix directly with other chemicals while treating.

Dried, unmixed Oxalic Acid should be kept in a cool dry place will not expire.
Mixed solution can last up to a week at room temperature and a few months if kept in the fridge.


*Some information gathered from Randy Oliver’s “Oxalic Acid: Questions, Answers, and More Questions: Part 1 of 2 Parts”;

Friday, August 21, 2015

Controlling Your Varroa Mite Counts

Varroa Mites are small, reddish-brown tick like pests that feed off the hemolymph (blood) of the bees. The exposed wound their bites leave make the bees easily susceptible to infections and viruses. Treatments will reduce the mite population but the real threat of winter loss is the viruses that persist after mite treatment. It takes two to three generations of brood rearing to reduce virus levels. Late fall treatments do not allow sufficient time for the development of healthy bees to take the colony through winter. The best time to deal with mites is late August/early September depending on your location to help get your hive ready for winter.

Before you start going out and buying medication, though, you should perform a mite count to assess the mite levels of your hive. You want to have a true understanding of the mite population to know if treatment is necessary. Having a hive free of varroa mites is a rarity, therefore, it is always best practice to apply a treatment to the colony(s) to knock back the mite population before winter.

One of the best ways to check for varroa mites is by using your IPM Screened Bottom Board. An IPM Bottom Board comes with a gridded corrugated sheet that you can transform into a ‘sticky board’. The gridded corrugated sheet helps when calculating your varroa levels. To run this test:

  1. Coat the gridded sheet with petroleum jelly or cooking spray to make the surface sticky.
  2.  Insert into the groove underneath the screen of the bottom board and leave there for three days.
  3.  After three days, remove the gridded sheet and count how many mites you spot. Divide that number by three and that will give you an average daily count.
  4.  During the Fall months, if your average daily count is around 50 or more you will want to look into some form of treatment to help keep it under control.
Another way to test for varroa is a process called the sugar shake method. It requires getting into the hive to test but it gives you quicker results:

  1.   Fill a mason jar with around 2 tablespoons of powdered sugar and then about 300 bees (roughly 1/2 cup).
  2.  Put the lid on the jar and gently tumble until the bees are fully coated in the powdered sugar. The sugar will coat the bees and loosen the grip of the mites.
  3.  Replace the Mason jar lid with an 8 or 5 mesh hardware cloth and shake the excess powder from the jar onto a white surface to help with counting (paper plate works great). The mites that lost their grip will fall out with the powdered sugar. Empty the bees back into the hive.
  4.  Spray the sifted sugar with water to dissolve the powdered sugar so you can have a clear view to count the mites. If you count 10 or more mites after your test then you will want to treat.
Your ultimate goal is to control the varroa population throughout the year so they make as minimal impact on the hive as possible.

As for treating Varroa Mites, there are two different types of medications available to treat with:

SOFT CHEMICALS: An effective treatment while leaving the least amount of residue. We offer MiteAway Quick Strips and Api Life Var. Both are 95% effective. They work through the evaporation of essential oils or organic acids, thus making them weather sensitive. Many in the scientific community strongly encourage the use of “soft chemicals”.

Another soft treatment that has been growing in popularity is Oxalic Acid. Having been a popular treatment in Europe and Canada for years, it has recently been approved in the United States. It is a naturally occurring acid found in plants and honey. The efficacy of this treatment is in excess of 95%.

HARD CHEMICALS: Will kill Varroa Mites but label instructions must be followed and do not leave on longer than recommended. We supply Apistan Strips, Check Mite Plus, and Apivar. Bees have been known to build up a tolerance to these treatments. Perform a mite count after treatment; do not assume it was effective.

NON-CHEMICAL: The Varroa reproduction is directly tied to the bee reproduction cycle. Because drones are capped longer as brood, the Varroa are more attracted to drone brood where they can lay more eggs. Using Drone Foundation or a Drone Frame, you can wait until the brood is capped, remove and freeze the foundation. DRONE FRAME MUST BE REMOVED ONCE BROOD IS CAPPED. Non-chemical or IPM techniques can be effective to control mites; however, they require dedication and time to be successful. 

Tuesday, May 12, 2015

Replacing a Queen

In order for a colony to survive they must have a fertile queen. 
A queen will be replaced in the event that something unexpected happened to her or, more commonly, the queen's fertility and pheromone will decrease as she continues to age. This act is known as supersedure (would be considered an emergency supersedure if the queen were to die unexpectedly)

In an emergency situation, worker bees will transform a cell with a fertilized egg into a queen cell. If the queen is being replaced because of age, the colony will develop a queen cell for her to lay into. 

When inspecting the hive for these queen cells, how do you know if the queen has been released or not?

Here are come photos that may help.

The above image shows a nurse bee attending to the larvae inside the queen cell. Worker bees will make thousands of visits to feed these larvae Royal Jelly. This royal jelly diet allows the reproductive organs and pheromone glands to develop fully.

The above cell is capped over, waiting for the queen to emerge. You can distinguish a queen cell by its size and texture. Because of the enriched diet and her elongated abdomen, a queen cell extends downward and is much larger than worker or drone cells. It takes on the texture of a peanut shell and the queen emerges from the bottom.


The virgin queen will emerge from the bottom of the cell. The first queen to emerge will go through the hive and destroy the other queen cells. This is done by cutting a small hole in the side of the cell and stinging those queens who have not emerged yet. 
The new queen will then go on a mating flight and return ready to begin laying eggs. If the new queen was developed due to an older, infertile queen, both queens may remain in the hive. Eventually the older queen will expire. 

Tuesday, April 21, 2015

Installing Your NUC

For those who have purchased a NUC (Nucleus Hive),
you are ahead of those who started with a Package. 

At the start they will have less bees than a standard 3 lb. package; however, because the queen is laying there will be brood in all stages and the NUC will grow much faster. Brushy Mountain Bee Farm NUCs consist of 3 deep frames of brood in all stages and 2 deep frames of honey and pollen. We personally go through each of our NUCs to ensure that there is a queen present. Having an established queen means there are less queen complications, such as queen acceptance, absconding, or supercedure with a NUC.

Here is a great video of a NUC installation but if you have the time to stay for our live demonstrations on our NUC Days you will be able to ask questions or voice concerns. 

Once your bees have been installed, a feeder must be applied. Careful consideration should be taken when choosing your feeder. Both internal and external feeders have their pros and cons. Entrance feeders have the advantage of allowing you to check the feed levels and apply more if needed without opening the hive. Internal feeders such as division board feeders and hive top feeders, allows for more feed to be applied to the hive and decreases the chances of robbing. 

Keep the feeder on until your bees are able to sustain themselves (even then, having a feeder on for that rainy day is recommended). If temperatures do not drop below freezing, a 1:1 ratio of sugar to water is an acceptable feed. The sugar water mixture will help stimulate colony growth. Add a feed supplement to increase the colonies growth and health. If colder weather is forecasted, feed with fondant or other semi-moist, hard feed. 

Tuesday, February 10, 2015

Frames and Foundation for your Hive

As we begin prepping for the year to come, beekeepers begin purchasing frames and foundation for their hives. Beekeepers always wonder what frames will work the best for their hives and what type of foundation they need for those frames. Almost any type of frame can be made to work with any type of foundation. There are certain styles of frames and foundation that work better together. 

Wooden frames are the most common used in the bee industry. They do require some assembly and will accept supports to hold the foundation sheets steady. With the use of support pinsrods, or crimped wire foundation, wooden frames will be able sustain the weight of the honey produced during the honey flow. However, when manipulating the frames in the hive, care must be taken not to crack or split the frames.

Wooden frames have two different style top bars and bottom bars. Top Bars either come as Grooved or Wedge Top, Bottom Bars as either Grooved or Divided. You can combine any combination of the top bar and bottom bar to make up your frame.

  • Wedge top with Divided bottom bar frames are typically used for beeswax or wired foundation. The wedge on the top bar holds the wax sheets in place.

  • Wedge top with Grooved bottom bar frames will use wax foundation (except for crimp wire foundation with a hook) or plastic foundation. The grooves will hold the foundation in place along with the wedge top. Wedge cleat may not be needed with plastic foundation.

  • The grooved top and grooved bottom bar frames are typically used with plastic or duragilt foundation. The groove on the top and bottom of the frames allows the plastic foundation to just "snap' into place while the grooves hold the sheet in place.
    It can also hold wax foundations except the crimp wire with hooks.

Plastic frames are growing in popularity for their durability and ease of use. The foundation is embossed with a cell pattern to help the bees form waxed cells. The plastic foundation will have a thin coating of beeswax to help the bees begin drawing out comb. These frames will last much longer than the wooden frames. However, bees may draw comb more slowly on the plastic foundation than on the wax foundation.

Foundation is a sheet of plastic or beeswax with an imprinted cell design. Some beeswax foundation is preassembled with wire supports run throughout to accommodate honey filled cells. The imprinted cells will provide a starting pattern for your bees to begin drawing out comb. the thin coating on the plastic or the beeswax foundation, gives the bees enough to work with until they develop their own. 

If you plan to attempt no foundation for your frames, your bees will not have a guide to use and your frames can get messy. If you try this attempt, we recommend the use of a starter strip. For the use of a starter strip, use the wedge top to hold the strip in place.