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Mite Away- A Proven Sustainable
Mite Treatment Regimen for Canada.
In the face of resistance to Apistan® and the potential loss of CheckMite+™ Canadian beekeepers need to have an effective, economical varroa treatment program at their fingertips. This article is about a proven treatment regimen using Mite AwayII™ Single Application formic acid pads (MAII).
In Canada the varroa and tracheal mite treatment windows are defined by winter and the start and end of the harvestable honey flows. Southern coastal BC is the exception, and will be addressed on its own, further in the article. So to keep varroa and tracheal mites below the economic injury level (EIL) treat spring and fall as laid out in the graph below (graph 1).
Graph 1
(click on graph to see full size version)
Why the MAII program works.
Like most living creatures honey bees and the varroa mites have two main goals in life: protection and reproduction. The honey bee protects itself in a variety of ways: hoards food for times of dearth, lives in a cavity for protection from the elements and predators, clusters to preserve heat, and, of course, stings. To reproduce the individual bees the colony raises offspring, to reproduce the colony unit it will swarm.
The varroa has the same goals. Varroa mite reproduction is tied directly to honey bee brood. It will reproduce itself to a point where it will kill off the host colony. For the “jar model” description of how the varroa population builds, see the article in the American Bee Journal called Varroa Doubling Info: Understanding the BOOM and Assessing your Varroa Treatment “time purchase” (VanderDussen, D. in press, ABJ, scheduled for May).
To protect itself when phoretic (outside the brood cell) the varroa mite wedges itself under the layers of the bees’ abdomen (sclerites), making it difficult to be groomed off. The mite reproduces under the capped cell, so it is protected during the reproductive stage. So critical is the cap for protection that when the cap is removed, the male mite and immature females die. Varroa do not appear to reproduce very well in winter raised brood. The reason is not yet clear, but the high humidity in the winter cluster may be a factor. Multiple adult varroa, up to nine in one cell, have been uncovered by researchers, apparently not trying to reproduce, just seeking a refuge.
As well as within the colony the varroa mite reproduces and protects itself by dispersal. Mites spread by hitchhiking on adult bees as they move between colonies.
Another way the honey bee colony protects itself is to produce two entirely different types of worker bees. A “winter” bee is produced at the end of the summer and into the fall. It may never see a blossom. It is physiologically different than the summer bee, with a different hemolymph (blood) protein profile than the summer bee. A winter bee will live much longer than a summer bee, and can perform colony tasks at different ages. Its sole purpose is to get the colony through until the next spring.
A “summer” bee is tightly programmed to perform tasks by age. Becoming a field bee, gathering the nectar and pollen that will be the food for the colony and provide the reserves for the colony’s survival through the winter, is a crucial task a winter bee may never have to perform. The bee population will naturally drop in the fall as the summer bees die off, to be replaced by the smaller winter cluster, as the colony prepares for the long winter months ahead. Spring dwindling is a well documented phenomenon that occurs as the winter bees die off and the replacement summer bee population has not yet surged ahead.
With a “soft” chemical treatment product like MAII, treatments need to be applied to protect each cycle of bees. The spring treatment will get the colony through the honey crop and into the fall in good shape, the late summer/early fall treatment gets the bees through the winter. It is important for the colony to raise at least one cycle of brood after the fall treatment is applied, to make sure enough healthy bees are in the colony to take it through the winter. Fortunately, a MAII treatment appears to stimulate the colony to raise at least a cycle of brood after the treatment is applied in the early fall.
Oxalic Acid:
With the oxalic acid treatment, performed when there is little to no brood in the colony late fall, it is too late for the bees to raise a healthy cycle of brood for winter bees. Oxalic acid treatments in the fall will not give enough control to skip a spring MAII treatment. An oxalic acid treatment early spring, before the colonies have capped brood, may be adequate to keep populations in check until the early fall treatment window, but the author is unaware of the results of any spring trials run in Canada. Results in Europe showed that, although significant varroa drops were achieved, spring treated colonies had the same varroa loads as the non-treated controls come fall.
So, what is the role of oxalic acid? If, for some reason, a colony has high varroa loads going into winter late fall, the phoretic varroa may stress the colony enough to affect its survival. Whether or not that stress is greater than the stress caused by the oxalic acid treatment is unknown.
The Risk of Skipping the Spring MAII treatment:
The need for a spring treatment is easy to miss because the bee population is growing so fast the danger is hidden. Come the end of July, the varroa population can be over the economic injury level (EIL)i, as shown in graph 2, putting the colony and crop at risk.
Graph 2
(click on graph to see full size version)
When the beekeeper discovers high mite loads mid summer due to skipping the spring treatment, the plan of action may be to pull off the honey and apply the MAII treatment early. This may not be adequate control, depending on the starting mite levels, and a second treatment may be required early fall to allow the bees to produce a healthy cluster for winter.
Environmental Varroa Pressures:
The label on the MAII pail instructs the beekeeper to treat all the colonies in the apiary at the same time to prevent cross infestation. It is tempting to not treat colonies the beekeeper thinks may be doomed, such as drone layers. However, these colonies can be major sources of varroa re-infestation. Other “environmental” sources such as feral colonies may keep varroa pressures high, so wherever you can knock down varroa populations it will help reduce the overall pressure in the area.
Southern Coastal BC:
The southern coastal BC area is a unique climate zone in Canada. The winters are not as harsh as the rest of Canada and brood is maintained in the hives for much more of the year. The article “Identifying Treatment Windows” available on the MAII website at www.Mite Away.com will help beekeepers identify treatment windows for their area. Because of the longer brood rearing season, three treatments a year may be required. Monitoring will be very important in determining soft treatment needs as the hard chemical treatments fail.
Cost of a the Mite Away Treatment Program:
Two single application treatments a year are required. The 2006 pallet price (960 treatments) directly from the manufacturer is $3028.80 or $3.16 each treatment plus freight. The cost per year, to control both varroa and tracheal mites, is $6.32. Individual pails (10 MAII pads) or pallets of MAII are available from bee suppliers across Canada. Ready to use MAII is the safest and quickest way possible to apply formic acid in a beehive. For more information call 866-483-2929 or go to www.Mite Away.com.
- Mites of the Honey Bee, page 234
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