Varroa Mite IPM: Mite Management Is the Bee's Knees!
Recorded April 23, 2019
Kim Skyrm, Apiary Program Coordinator/Apiarist, Massachusetts Department of Agricultural Resources
Jen Lund, Apiarist, Maine Department of Agriculture, Conservation and Forestry
Additional Questions and Answers
Alcohol wash and mite counts
Q. When do you recommend doing the first mite count?
A. I recommend doing one during your very first full inspection for the year.
Q. How often should you do the alcohol wash?
A. At least once a month and after you do a treatment—to check to make sure it worked.
Q. Rubbing alcohol?
A. Yes, 70% is typically used.
Q. We use windshield washer fluid. It has a lot of alcohol, and is cheaper.
A. Windshield washer fluid can also be used effectively.
Q. When doing an alcohol wash, should I take the bees from a capped brood frame or uncapped?
A. Uncapped, that is where you will find nurse bees which you want to sample.
Q. What if you have a new nuc, when do you do the first wash? Or when do you do the first wash for a new package of bees?
A. You can do a mite wash as you install or right after you install.
Q. With a brand new hive with packaged bees, can the alcohol test stress the hive too much if done before first brood emerges?
A. There are about 10,000 bees in a 3 lb package, so losing 300 should be okay.
Q. What are the most effective treatments?
A. This is a difficult question to answer—how well any treatment works depends on what time of year, if you are making honey, and what the outside temperature is.
Q. Can you comment on the use of heat therapy in the hive as a varroa mite therapy?
A. Unfortunately the current products for heating the hive do not work as well as we would like them to. The results tend to be very variable. Also the bees “fight” against the added heat by ventilating.
Q. Do the 50 percent losses in Massachusetts come from treated hives?
A. Thanks so much for your question! We do not ask if the losses come from treated hives, but great suggestion that we should! We ask separate questions about overall apiary management that include questions about mite treatment and mite counts pre/post treatment.
Q. I understand that we shouldn’t use Apivar with honey supers on the hive. But it seems like an effective emergency therapy, when you’re not sure the weather will cooperate with formic acid. Is there a point where, if you do have a super that’s been on a hive where you were treating with Apivar, it becomes safe for general use? And can you feed that honey to the bees, whether or not it’s safe for people? (The European and New Zealand data sheets seem different from the U.S. sheets on this point, and as you see, I’m hopelessly confused.)
A. You should not use Apivar when there are honey supers on the hive. Remember, the label is the law and should be followed for the safety of both humans and bees. If there was an emergency situation in the middle of the summer and it is too hot for formic treatment you can always use HopGuard 2. It can be used during a honey flow and has no temperature constraints. If you have honey that has been exposed to Apivar, you can feed that back to your bees.
Q. Can you please talk again about rhubarb? I have heard a lot of positive news about this, but I don’t know how to use it. Thank you!
A. There is no scientific evidence that this has any effect on Varroa.
Q. Can you treat as a preventive measure, no matter how many mites you count?
A. We discourage prophylactic treating. 1) It may be unnecessary. Why waste the time/money? 2) Some of the treatments can impact the bees negatively. Why risk unnecessary treatments? 3) You may miss a mite problem. Two summers ago a drought in S. Maine caused mites to explode earlier than normal in the year. Those beekeepers who were monitoring caught it, those that were treating on a schedule and not monitoring had dead hives by Halloween. 4) Repeated treatments can lead to mite resistance.
Q. If the goal of IPM is to reduce chemical usage, which of the cultural techniques works best in our area at suppressing mite numbers? Are you enamored of any genetic answers?
A. There are a lot of options and all have a place in IPM of varroa mites. We are hoping to provide a series of webinars later in the year that will be focused on Varroa biology, growth and treatment where we will spend more time exploring the many non-pesticide options for controlling varroa mites—stay tuned for more info!
Q. Does old bee bread retain diseases? Should you discard or reuse?
A. The current understanding is that most viruses remain viable for about 6 weeks after the bees all die. After that it is safe to reintroduce bees. There is a lot of research currently underway looking at virus survivability under different situations (overwinter, in the hot south, etc.).
Q. Why not treat when under 5 mites per 300?
A. Treatment threshold is usually 2–3%. This is 1.6% and below threshold.
Q. I lost my bees over the winter. I checked for mites with alcohol monthly with mite levels 4–5, so I treated each month. Why did I lose the bees?
A. Your best bet for getting an accurate answer is to have your hive inspected. It’s possible, even with ample stores available in the hive, that the bees starved to death. If they have started rearing brood, the bees will not move away from brood to get to food if it is too cold.
Q. How effective are hygienic or VSH bees in resisting varroa mite infestation? Is there any way to add these to an existing hive?
A. They can be a good tool to help slow the rapid buildup of mites throughout the season, but often are not enough to keep them completely suppressed and intervention (miticide) may still be necessary. They fall in the “prevention” portion of the two prong attack to varroa mite management. You may still need an “intervention” from time to time. To add them to a hive, you would purchase a new hygienic queen and replace your existing queen with her.
Q. Can you provide more information about the mite workshop for Eastern Massachusetts?
A. Information for the one being held in Amherst on May 4 can be found here: http://ag.umass.edu/pollinators/events/fight-mite
Q. Where are the two Massachusetts apiary sites?
A. Information and addresses for both Massachusetts State Apiaries are listed here: https://www.mass.gov/service-details/mdar-state-apiaries
Q. What was the website with map showing mite counts?
Q. I suggest an intro and advanced session, maybe based around who has used alcohol wash and who has not. For those of us who already monitor by alcohol wash, this webinar was mostly a waste of time.
A. We are hoping to provide a series of webinars later in the year that will be focused on Varroa biology, growth and treatment where we will spend more time exploring the many non-pesticide options for controlling varroa mites—stay tuned for more info!!
Q. Next time please talk about the risk that non-treatment beekeepers pose to other beekeepers, and the unfairness of it. It took me years to understand this!
A. There is a thing we refer to as the “mite bomb” effect. When a queen dies in a hive infested with varroa/virus, the remaining bees will abandon their home and find new hives to live in. A researcher a few years ago painted every bee in a hive that was collapsing from varroa and let it collapse. Afterward, she sampled every hive in a 2 mile radius and found marked bees from the collapsed hive in it. The bees from the collapsing hives bring their mites/viruses with them and can cause an increase in mite numbers for the “bombed” hive.
Q. How can you tell the difference between drone cells and queen cells? Thank you!
A. That is a hard question to describe without pictures. Google drone cells and queen cells and you should be able to find some good photos and descriptions.
Have honey bees? If yes, this presentation is for you! Join Kim and Jen to get the latest update on national and regional trends in honey bee health along with the tools necessary for managing the most detrimental pest affecting honey bees, varroa mites (Varroa destructor). They will discuss the life history, monitoring, and management techniques involved with varroa mite control. Participants will also be led through a real-life case study to allow for a better understanding of how to monitor mite populations, determine the signs of a high varroa mite level, diversity of treatment options available and action steps to take after treatment to ensure efficacy. This presentation will provide the most direct benefit to beekeepers or those wishing to become a future beekeeper, but others with interest in honey bee health are also encouraged to attend!
About the Presenters
Dr. Kim Skyrm has been the Chief Apiary Inspector and Apiary Program Coordinator at the Massachusetts Department of Agricultural Resources (MDAR) since August 2015. Prior to this appointment, Kim was a Post-Doctoral Researcher at the University of Massachusetts-Amherst working with bumble bees in cranberry pollination. Dr. Skyrm is a scientist by training and a hobby beekeeper. Having experience in academia, industry and now government, Kim has always been driven by an intense love of bees to serve in roles supporting bee pollinators informed by the latest scientific research. This is evident given that Dr. Skyrm has been working with native and managed bees, beekeepers and farmers for the past 12 years through outreach education, research and extension type projects. Kim is truly passionate about apiculture and ensuring the viability and sustainability of bee populations!
Jennifer Lund has a Master’s degree in Entomology from the University of Maine and has over 20 years of entomological experience. Before becoming the Maine State Apiarist in 2016, Jen was a research technician in the entomology department at the University of Maine in Orono (UMO). While at UMO, Jen worked on many honey bee projects including a national colony collapse disorder study, honey bee colony health comparisons of top bar and Langstroth hives, integrated varroa mite control effectiveness, the role of honey bees as vectors of blueberry disease, sub-lethal effects on colonies to low-level pesticide exposure, and health of migratory hives arriving in the State of Maine for blueberry pollination. Jen is passionate about honey bee health and helping beekeepers succeed. Aside from managing the honey bee inspection program and helping Maine beekeepers protect their hives, Jennifer also has several of her own hives that she maintains on her farm in Maine.