10 Questions Using Tools for Varroa Management Dewey M. Caron Emeritus Prof U Delaware Affiliate Faculty Oregon State Univ The Honey Bee Health Coalition was formed in 2014 as a cross-sector effort to promote collaborative solutions to honey bee health challenges. The diverse Coalition brings together beekeepers, growers, researchers, government agencies, agribusinesses, conservation groups, manufacturers and brands, and other key partners dedicated to improve the health of honey bees and other pollinators. The Coalition’s mission is to collaboratively implement solutions that will help to achieve a healthy population of honey bees while also supporting healthy populations of native and managed pollinators in the context of productive agricultural systems and thriving ecosystems. A major tenet and founding principle of the Coalition is the recognition that the current Publication just released in 2015. http://Honeybeehealthcoalition.org/varroa/

Congratulations WASHINGTON CAPITOL SOON TO BE HOME TO 30,000 HONEY BEES

BAD NEWS stole 4 or 5 frames from each of 21 of the colonies.

What is really happening? The Loss Crises in Bees! Beepocalypse Epidemic of bee Losses Unprecedented levels of bee losses Are Bees going extinct?

42% 4-yr Avg 37% 23% 9-yr Avg = 29%

Loss by beekeeper by colony size

Self-reported ‘reason’ for loss

1. True or False? Every honey bee colony in the continental United States and Canada either has Varroa mites today or will have them within several months.

TRUE . We all need to accept the fact that we have an extra member of the family – the mite – and it’s here to stay. You may manage bees well but now you need to do the same with regard to the Varroa mite. Honey bee Coalition and Randy Oliver; Scientific beekeeping. Goal is to get to know varroa mites, determine numbers and how to manage them. Doing nothing about Varroa mites is not a practical option for most beekeepers. Honey bees are not capable of surviving or thriving unless the beekeeper prevents Varroa from reaching damaging levels. Honey Bee Coalition

2. Successful Varroa control systems are ________ We need to control Varroa before the mites reach levels that threaten colony productivity & survival. All beekeepers should remain vigilant to detect high Varroa mite levels and be prepared to take timely action in order to reduce mite loads. Successful Varroa control solutions are proactive. They control Varroa before the mites reach levels that threaten colony productivity and survival, rather than respond after the damage has occurred. Integrated Pest Management

3. Varroa mites found outside of capped brood are called Phoretic Varroa mites are found two ways in a bee hive. It is important to consider that the Varroa mites, because of their life cycle, spend 2/3rds of their time under capped cells and one third as exposed phoretic mites on the outside of a bee. This will be an important consideration later when we consider different methods of control. Reproductive phase

4. What are the 4 four population phases of the honey bee/Varroa mite seasonal cycle Honey bees and their Varroa mite parasites cycle through four temporal phases. In some locations, there is one cycle per year and, in other locations, more than one cycle. The phases are: Dormant Population Increase Population Peak Population Decrease Different control options are appropriate for each of the four population phases of the honey bee/Varroa mite seasonal cycle. Before we start: mention year round screen bottom board and axiom: treat one, treat them all.

Fall: Population Decrease Bee population versus Varroa population 5. True or False? The same level of mite infestation poses different risks during different phases of the bee/mite annual cycle. TRUE TrueBe very careful interpreting results from any single sampling technique. Inexperience with sampling procedures will affect results. Mite infestations vary from one colony to the next. The same level of mite infestation poses different risks during different phases of the bee/mite annual cycle. Losses can be expected even at a 3 percent infestation, and can increase rapidly with higher infestation levels. Fall: Population Decrease Bee population versus Varroa population

6. What percentage mite infestation is considered to be potentially harmful? 5%. If post-treatment tests show that mite numbers remain above 5 percent after treatment, apply another control chemical or method without delay.

7. We recommend powdered sugar or alcohol wash to estimate mite populations. WHY?

Both methods tabulate the same way… Collect a sample of approximately 300 adult bees from one to three brood-nest combs (avoiding the queen). Add powdered sugar/alcohol and shake for at least 1 minute; repeat Count the number of mites collected in the plate or pan. Divide that number by the number of bees in the sample. Multiply by 100 to yield a percentage. Three hundred bees are equivalent to about ½ cup of lightly packed bees. A beekeeper samples 300 adult bees and counts 12 mites in the pan. 12 mites ÷ 300 bees = .04 X 100 = 4% (4 mites per 100 adult bees)

Can I use a sticky board to estimate mite loads? Or Drone brood? Ants or other scavengers might remove mite bodies and interfere with estimates. Difficult to interpret number of mites per hour or per day to estimate total mite population. Less reliable sampling method -Not recommended

How are your mite numbers trending? The trend is what is important Watch for false negatives Late season: (August) Less than 25 mites on the collection board/24 hour period Early season (March) Less than 10 mites on the collection board /24 hour period Mites on a collection board. I prefer to use the more conservative number. Example of number varying with population. All you get is a trend. Point: not necessarily the actual numbers but the trend. Different meaning if you have a small colony with three frames of bees vs one with 20 frames. Question: How many mites equal a problem. The goal is to keep the mites under an economic threshold. You will never totally get rid of them. In spring the threshold is 15 mites/day. If you have this number or more, it means you will want to treat. False negative. Put the collection board in and don’t get any mites. What does this mean? Look further. Look up at screened bottom board with a mirror. If it is covered or plugged with trash, then the mites won’t be able to fall through to the collection; hence the false negative. Another way. If you forget to spray the collection board with cooking oil, the ants will climb up and rmove the mites hence giving you false positive results.

8. True or False? While mite densities may vary across colonies, all colonies in an apiary should be treated at the same time with the same chemical or non-chemical technique. YES NO While mite densities may vary across colonies, all colonies in an apiary should be treated at the same time with the same chemical or non-chemical technique. If sampling results indicate high mite populations in one colony within an apiary, do not delay treatment. Delay increases the risk of harm to the colony and the spread of Varroa mites to other colonies.

9. What is IPM? (IPM) is a set of proactive, non-chemical and chemical methods that offers beekeepers the best whole systems approach to controlling Varroa.

What controls work?

Non-chemical controls used for mite control Minimally effective Screen bottom board Comb culling Powdered sugar Apiary site Colony configuration Basic sanitation Drone brood removal Brood interruption Requeening See pages 17-20 for description of each. May spend time reviewing the pros/cons of these methods. More effective

What chemical controls work?

Synthetic chemical treatment What is another name for Apivar? What is its mode of action? Can it be used when supering? What about disadvantages? Amitraz Contact No Brood loss, developing resistance?

2 older Synthetic Chemical Treatments What is the active ingredient of Checkmite? What about Apistan? What are major disadvantage of these two treatments? coumaphos Tau-fluvalinate contamination of hive components; long half-life Mite resistance beeswax contamination Kill queens

What other chemical controls work?

APIGUARD Essential Oils Treatments Thymol Fumigant Naturally derived What is the main ingredient of both products? What is the mode of action for these products? What is an advantage of these product? What are issues when using these products? Thymol Fumigant Naturally derived Temperature Brood/queen loss

What other chemical controls work?

Acid Treatments: MAQS What is the active ingredient of this treatment? What are two major advantage of this product compared to others? How does temperature affect use of this product? What considerations does the beekeeper have to keep in mind when using this product? Formic acid Kills mites under caps & can use when supering Mode of action: fumigant Can’t use >90 degrees Personal protection essential; gloves, eye wear, respirator

Acid treatments: Oxalic What is the mode of action? What are the 2 methods of application? What time of year should this product be applied? What is the major advantage of this product? What about disadvantages? Contact Dribble & vapor Dormant phase, population decrease Apply when broodless Corrosive Hopquard II

The BOND method ONE thing we all can do -- Varroa mite BMP/IPM MUST DO alcohol wash MUST DO These are all “HARD” to do Essential oils hard miticides Apivar MAQS Oxalic HopGuard Ii acids NOBODY “likes” these The BOND method

What is your favorite “word” to describe your beekeeping?

Some seasons/colonies are going to be tough…. For every complex problem there is an answer that is clear, simple and wrong H.L. Mencken