The Beekeeper’s Companion Since 1861
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Bees & Beekeeping: Present & Past

An Illuminating Encounter with a Usurpation Swarm

- December 1, 2022 - Wyatt A. Mangum - (excerpt)

For years, I have maintained a bee house that holds 30 single-comb top-bar observation hives. The building is a 12-by-24-foot structure moved to a site on our property and extensively modified to become a bee house (see Figure 1).

For example, I removed the two windows, turned them upside down, and reattached them back into their openings. Then I painted the glass black. These strange window modifications made perfect sense for a bee house. When I open the observation hives for various studies, invariably releasing some bees inside, they fly to the brighter windows, even painted. Bees obstructed at a window crawl up, not down. A regular window, opening at the bottom, is a poor design for a bee house. My modified windows function more naturally with the way bees try to escape from a window. They crawl up and find the open slit, which releases them.

Each top-bar observation hive holds one comb. A hive’s entrance pipe from the outside is horizontal. The hive rotates on its vertical entrance pipe from a “T” connection under the hive. By turning the hive, I can easily see both sides of the comb or follow a bee as it switches comb sides. I built the hives from scrap wood and fit the PVC entrance pipe sizes together, forming a pivot from where a hive rotates without any disturbing vibration (see Figure 2).

As also seen in Figure 2, only my homemade metal clips and duct tape hold the glass to the triangle comb supports. I made the hive so it could be opened in 30 seconds or less. The bare edge glass may seem too sharp to safely handle, but a simple solution avoids injury. With a fine grit sandpaper, I smoothed the sharp edges of the panes (both sides) and even rounded the corners of the glass. Overall, these observation hives are not for general public display.

For numerous projects to study various beekeeping problems, my next bee house (possibly two of them) will have larger observation hive colonies in multiple tiers of frames (like a regular frame hive). The concept is to have essentially an “apiary” of observation frame hives in a bee house. These observation hives are more complicated to build, and I do not have a wood shop, so I decided to buy them. Since they are quite expensive, I have been buying them a few at the time over several years, accumulating 20 (with the goal of 30 for statistical reasons).

Some of these observation hives are in medium frames, four tiers high and three frames wide for a total of 12 frames. Other observation hives are the same design, but in deep frames, three tiers high and three frames wide for a total of nine frames. For either frame size, it costs one frame-hive colony to start each observation colony (with the extra frames and bees going to other hives in the out-apiary).

With a bee house apiary of say 15-20 of these observation hives, I can watch them all through the spring, especially in our dearth summers and through the winter days and nights in regular light and with thermal cameras (see Figure 3). The observation hives have screen floors and plastic slides that can function as sticky boards.

Eager to begin working with these larger observation hives, I decided this year to transfer about a half dozen colonies from my frame hives into these large observation hives. When working with an unfamiliar hive design, especially for formal research, it is important to have already learned any restrictive logistics or special handling required by the hive design before data collection begins. First off, I confirmed I could only haul one hive at a time (see Figure 4). For managing up to 30 of these observation hives, I need to build something to hold at least five in the bed of the bee truck. Figure 5 shows the large observation hives in one part of the bee house with the smaller top-bar observation hives on the upper row.

For one large observation hive, made for medium frames, I wanted the two lower frame positions occupied by one row of deep frames. That substitution would leave several inches of open space below them to the screen floor. In the spring a growing colony would avidly fill that space with comb. In the fall, during a meager nectar flow, the conditions are hardly conducive to comb construction. Until spring, I would have a good view of the screen floor, and what fell on it from the colony above. I could watch the pattern of trash forming on the screen and on the plastic insert below.

Arriving at an apiary with top-bar hives and frame hives separated by a thin partition of small trees this summer, I parked near the frame hives. Immediately, I saw a massive complication to the day. A small swarm was on a branch above the frame hives (see Figure 6). Beginning in June, well past the spring nectar flow (and the spring reproductive swarm season), I look for small swarms in any apiary I enter, the time I call usurpation season (see Figure 7).

With these summer swarms one needs to be mentally nimble and quickly break out of old ruts of outdated beekeeping. First off, do not assume that swarm came from the frame hives in a circle under it, or even the dozen top-bar hives just over the trees in the other part of the apiary. The little swarm could have come out of the woods from some other unknown managed colonies or a bee tree. And just as wrong, do not assume the little swarm will leave like a spring reproductive swarm (although it could). Furthermore, do not think this meager little swarm is doomed, like beekeepers knew when I was a kid. Never mind that the end of the active bee season looms near. Oh yes, the cold is coming. Do not fret one bit that the little swarm has not a drop of winter honey and not even one bee cell to call a comb.

When moving closer to these swarms, it is normal to look up at them –– but before approaching these swarms –– look down, intently, especially under the swarm cluster. By situations and conditions that I am still trying to resolve completely, queen balls sometimes drop from these summer swarm clusters (which can be larger than the cluster shown in Figure 7).

Veteran beekeepers are accustomed to walking under a spring reproductive swarm in a tree, studying the cluster from various lower perspectives, pondering out some plan to hive it. While figuring, they are not concerned about stepping on any of its bees (unless a night storm tore out chunks of wet and cold parts of the cluster and scattered them on the ground). Under a summer swarm, I have found up to a half dozen queen balls (others have observed many more). No queen balls were under the little swarm, which currently I see as a lack of interruption as the swarm continues on to invade a colony.

Even late in the summer, blending into early fall (September 20, 2022), this swarm automatically makes me think it wants to take over one of the nearby hives. Until the swarm exhibits that behavior, I usually regard it as potentially a usurpation swarm, although I will at times just call it a usurpation swarm before it has committed to taking over a colony.

Even up in the tree, I could see a couple of bees waggle dancing on the cluster. I know that bees forage for nectar from these summer swarms. I have even seen very small summer swarms, comprising only a couple dozen bees, with waggle dancers and returning foragers feeding two or three bees at a time. The waggle dances would indicate distant nectar sources and not nest sites as normally occurs with spring reproductive swarms. (Even before usurpation, foraging by a summer swarm is a fundamental difference with a spring reproductive swarm, whose bees do not forage.)

Overall the swarm in the tree seemed fidgety like it would soon launch. With the small swarm out of easy reach, I decided not to bend the branch down to capture it. (I could have thrown a long nylon tow strap over the branch and bent it down to bring the swarm within reach, a typical beekeeper maneuver. I keep all that kind of swarm-catching gear packed on the bee truck, ready for quick action.) Instead, I resolved to just watch the swarm as I transferred a colony to a large observation hive. Sometimes you learn more about bees by not intruding on them, even when you can.

I knew this plan had a bad flaw. The bees from the frame hives, ten hives in a circle below the small swarm, had found some minor nectar source. Their collective flight was loud enough to produce a decent hum. When the small swarm took flight, it would become a very diffuse bee cloud as I have seen and video-recorded. The small swarm hum would be drowned out by the general apiary hum. If I became too involved with transferring the bees, which delayed me too long between visual checks, I might look back and the swarm cluster would have   ….