My interns (James and Joanna) and I recently installed pollen traps on our observation hive at Tufts University. We installed the pollen traps to control which amino acids our bees eat. Since pollen is basically the bees’ only source of amino acids (there are small amounts of amino acids in nectar), pollen traps allow us to control which amino acids our bees eat while letting them forage freely. The trap is metal mesh with openings just large enough for a bee to get in—without her pollen pellets.
First, we tried 5-mesh hardware cloth (which means there are 5 squares to an inch of mesh). After watching the bees for a bit, Joanna noticed that a lot of the bees were getting through with their pollen. So, I did what any ecologist might have done while in the field. I googled it (hooray for smartphones!).
Turns out, our 5-mesh was only about 60% effective at removing pollen from bees’ legs. What we needed was 6-mesh (6 squares to an inch). So we walked to the local hardware store (another classic ecologist move). There, we found that “6-mesh hardware cloth” is beekeeper talk.
The man at the hardware store had no idea what I was talking about. So I called Home Depot. They didn’t know what I was talking about either. Then, I called Bill Perkins of Agricultural Hall (who I should have called in the first place). He knew what I was talking about but he didn’t have it. Bill gave us some leads and we finally found our nearly 100% effective (nothing’s ever 100%, right?) 6-mesh hardware cloth (had to order it online).
When it arrived, we installed the 6-mesh hardware cloth; it was clearly a lot harder for the bees to get in and out. This was expected. Unexpectedly, however, the bees started getting really upset with the roadblock. Two of our hives had such a bad traffic jam that I think they started looking for new homes! Hive H (Hill Hall) and B (Barnum) each had a large cluster of bees right outside the entrance/exit. What’s more, bees were dancing on the surface of each cluster.
When it comes to a cluster of bees outside the hive (i.e. a swarm), dancing bees likely means that the bees are in search of a new home. These dancing bees are called scout bees; they use the waggle dance in the same way that foragers do. Instead of giving information about food, however, scout bees are giving information about a possible new home. Once the bees reach a consensus (via dancing), they move into their new home.
Needless to say, we didn’t want our bees to leave. We took off their pollen traps and I caught the clusters of bees that looked like they might leave. I put these bees in a nuc (smaller hive box) and moved the nuc off to the side. This way, if the bees were planning on moving out, I now had another colony!
And if the bees were only mad about the pollen trap, they could move back into their now-pollen-trap-free hive. Not sure what the verdict is yet but I do know one thing: 6-mesh pollen traps and observation hives don’t mix. The entrance/exit hole is just too small.
Back to the drawing board.
(We were still able to collect some beautiful pollen though.)