This is Part 2 of our bee inspection story. If you haven’t read it yet, start with My First Bee Inspection, where Maryland state inspector Dean Burroughs first walked our hives. This post picks up a few seasons later, when a second inspection came back with a Nosema diagnosis.
I am not at all scientific. I am a fourth-year beekeeper with an enthusiastic outlook and a few books under my belt.
My beekeeping success has only been made possible by a 76-year-old man named Dale Large. Dale is a 50-year beekeeping veteran who is by my side each visit to our hives. He is not at all scientific either, but he is a bee-whisperer. He handles them well, much more confidently than I do. We find issues together and we read about the issues, but we don’t always have the answers.
I filled out the bee survey last year and the Maryland Agriculture Department reported that I lost my bees again (18 hives). I was placed into the Maryland State Bee Study, which appears to be a joint effort between the University of Maryland and the Maryland State Environmental Protection Agency. (Some of the paperwork says University of Maryland and some says EPA.) The head of Apiculture, Jerry Fischer, and Dean Burroughs, our local bee inspector, came out to our apiary and took samples from two rows of hives on May 19th, about a month after I installed nucs. The hives were strong. There were 4 to 10 queen cells in each of the brood boxes, and it looked like they were all about to swarm. They were storing honey already. It was amazing how healthy they all seemed.
The results of the study were very faintly printed and hard to scan, but they stated that I was in the 90th percentile for Nosema, and that the bees had a virus that affects the shape of their wings.
When I started down the “why are my bees dying” road, some of the consultants I had asked in the past were convinced I had a varroa mite problem. It’s common here. But at the time of the study, out of roughly 658 bees, there was only one mite. I was in the lowest percentile for varroa. That could be misleading, though, because in my experience varroa doesn’t turn into a real problem until around August. If you want the fuller picture on that pest, we cover it in our guide to varroa mite detection and control.
I had a million questions about treating for Nosema, or even whether I should treat at all (I think I should have). Did being in the 90th percentile mean my hives were all infested? I wrote the lab director at College Park to ask. I didn’t hear back. I tried to reach the bee inspector, but sadly he had a stroke shortly after our visit, was out for a while, and has since retired. The language on the report was so vague that I brought in a friend who is a lawyer and asked him to interpret what he thought it meant. He agreed that the 90th percentile was bad news.
My other questions were the practical ones. What do you do to treat for Nosema? When do you treat? Which options involve the fewest chemicals? Are there gentler approaches? Do I have to strip out all the comb and start over? How do the bees handle this time of year? If I had to irradiate equipment, where and how would I do that? Did I need the honey inspected?
I had no idea what the next steps were. My books pointed toward fumagillin-b, and so did the beekeepers I trusted. My local bee inspector and a farmer friend both suggested it. Before I went that route, I dug a little deeper and read that apple cider vinegar added to feed, roughly 3 tablespoons per gallon of sugar water, might help. I went with that for all 18 hives.
Looking back, I probably should have reached for the fumagillin-b.
It’s a little like being really, truly sick: sometimes the gentle approach isn’t enough and you end up at the doctor for a Z-Pack. My bees needed a Z-Pack.
From the outside, everything looked normal that season. In fact, the harvest came in much stronger than the year before.
So what is Nosema? It’s a gut condition in honey bees caused by a microsporidian parasite. It tends to take hold when bees can’t leave the hive for long stretches of cold weather. Honey and sugar water contain solids that bees can’t pass while they’re confined, so without “cleansing flights” the spore load builds up inside them. Depending on how bad it gets, it can be hard to recover a colony without starting fresh.
And that is exactly what we planned for the next season. We acquired mostly all-new equipment and chose not to recycle last year’s comb. We started fresh and hoped for the best.
If you’re newer to all of this and want to see where our inspection story began, go back to Part 1, then read how we get the colonies through the cold in winterizing the bees.
FAQs About My Bees Needed a Z-Pack: A Nosema Diagnosis (Bee Inspection, Part 2)
What is Nosema in honey bees?
Nosema is a gut condition in honey bees caused by a microsporidian parasite. It often takes hold when bees are confined to the hive during long cold stretches and cannot take cleansing flights, which lets the spore load build up inside them.
What were the signs of Nosema in our hives?
In our case there were no obvious outward signs at all. The colonies looked strong and were storing honey, and the harvest was actually larger than the previous year. The Nosema only showed up through the state bee study sample, which placed us in the 90th percentile.
How did we treat our hives for Nosema?
We added apple cider vinegar to the bees’ sugar-water feed, about 3 tablespoons per gallon, across all 18 hives. Our books and local beekeepers also pointed toward fumagillin-b, and in hindsight that may have been the stronger choice. Treatment decisions should always be made with your local apiary inspector or extension service.
Is Nosema related to varroa mites?
They are two separate problems. Nosema is an internal gut parasite, while varroa mites are external parasites that feed on bees. At the time of our study we were actually in the lowest percentile for varroa. You can read more in our varroa mite control guide.
Do you have to replace equipment after Nosema?
It depends on severity. In our case we chose to start fresh with mostly new equipment and did not recycle the previous year’s comb. For badly affected colonies, replacing comb and equipment is one way beekeepers try to reduce the lingering spore load.
