For Your Consideration,

Some years ago, I remember reading on Randy Oliver’s page his discovery of a threshold with regards to varroa. As I recall, it was at around 3,000 mites in a standard colony. When that threshold was reached the colony would enter an unrecoverable death spiral. At that mite load, and accompanying virus load, the colony simply could not recover from the viral illnesses. Even if the colony looks viable it’s doomed. It’s fatally ill.

I think it’s worth frequently repeating that it’s the viruses that deal the final blow. We focus on the vector so much that often our sole effort is directed at the mites. Kill the mites is our mantra. And there is a bit of truth to that. Certainly, if we could eliminate the mites our problems would disappear. But after about 30 years we’re still experiencing the same problems with managing acceptable mite levels in order to have acceptable, sublethal virus levels.

Some things that have always bothered me are the ever-changing acceptable and unacceptable levels of varroa. Especially, Economic Injury Levels (EIL). The Economic Injury Level (EIL) is a concept that defines the pest density at which economic damage occurs. It helps farmers make informed decisions regarding the need for pest control. The EIL is determined by the cost of damage relative to the cost of control, and it serves as a threshold for applying control measures to prevent further economic damage. I’m sorry but I can’t get behind this way of thinking. As humans do we consider the price of treatment for ourselves versus how ill we may become if not treated? I guess, unfortunately sometimes we must if we don’t have the financial resources. But with our honey bees we do have the resources. The choice to treat always favors treatment. After all, what’s the cost of a new colony vs saving an existing colony?

So, over the years we have jumped around on what constitutes a level of mites indicating treatment is warranted. When I started keeping bees about 15 years ago the rule of thumb was always monitor your mite load and treat when it’s over 5 mites per hundred. Of course, later that number came down. And consistently, I heard that, one should always treat in the fall – period, hard stop! I found that I couldn’t usually wait until fall and couldn’t wait until that magic mite:bee ratio was reached if I wanted to stop the mite bombs from exploding and decimating my bee yard.

I also saw something else. My bees were sick long before they died. Being workaholics, hoarders and industrious they always did the best they could, but they just didn’t perform the way the bees did in the old-school books I read. I decided to do a better job and monitor mites all year and treat before a crisis developed. By this time, it had become mainstream to monitor more frequently but that EIL remnant lingered. I had already formed a negative opinion of relying on the officially decided EIL level would be in any particular year. Instead, I would go rogue. I noted that colonies crashed with some consistency following harvest, through our hot late summer, and many never made it to fall. So, I treated when I felt it necessary both seasonally, at lower mite levels, and before reaching the latest prescriptive level.

What I learned along the way was my bees not only started surviving, they also started thriving. The first time I noted the difference between bees that thrive and bees that are sick was in the spring of one year. For a couple of years, I had been treating with oxalic acid in December during the brood break. That year, I decided to administer oxalic acid treatments in early December, January, and February. During that year’s early build up I witnessed an enthusiasm on the landing board, as well as the prettiest fuzzy bees I had yet to see earlier in my beekeeping. They had it all and made lots of honey that year as I broke through honey production expectations. I couldn’t help but wonder if individual bee life expectancy had increased as well as overall health. I suspect both longer lived and healthier bees was a result of those early season treatments that cleaned them up reducing their viral loads. They felt better and it showed.

In the years that followed I came to believe that varroosis (death by varroa, or perhaps more accurately, by the viruses they transmit) was not an acute occurrence. That while it appeared to occur suddenly and acutely, I believed the evidence indicated varroosis was a chronic disease ending with sudden death. The bees were sick all along as the virus levels steadily increased throughout the nectar producing season. Steadily getting sicker and sicker, living shorter and shorter lives, working less and less, until finally the viral load crossed a lethal threshold and then, it presented as a sudden death. But it wasn’t sudden. They were becoming sicker every day that followed that last pre-season treatment. Why was it an acceptable practice to let our bees reach death’s door before we intervened? Why did we only treat them for an acute illness rather than a chronic illness? Acutely vs chronic management differs and perhaps we were travelling the incorrect path.

With human healthcare we manage chronic health problems like diabetes, heart health, high blood pressure, HIV (virus levels), and the like. We also have a different management practice to manage acute health problems like colds, flu, infections, and trauma. So, which do you think our bees are displaying with regards to varroosis? Is the viral load a chronic problem or an acute problem? Should it be managed only when your bees are at death’s door and reach an arbitrary EIL level or should we manage them as one would with a chronic illness? One might say that use of typical mechanical and cultural IPM methods is treatment along the lines of chronic management. That is true to some extent, but I’ve never seen any IPM treatments successfully mitigate the need for more aggressive treatments. Maybe our typical IPM methods slow the villain, but he steadily drags them down over time and eventually kills the bees.

So, if you’ve read this far, tell me what you think. Are our problems with mites and viruses acute or chronic? If you think the scale tips towards chronic perhaps we need a change in our treatment plan. What solutions might we offer to change the way we help our bees not only survive but truly thrive throughout the year?