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Bees & Beekeeping: Present & Past

Reversing Hive Bodies in the Spring: Shown with Large Observation Hives

- April 1, 2023 - Wyatt A. Mangum - (excerpt)

Last year I installed bees in large multi-comb (wide and tall) observation hives with frames (when a usurpation swarm interrupted my work). [See “An Illuminating Encounter with a Usurpation Swarm,” December 2022.] This article continues that work, showing one of its benefits.

These observation colonies went in my bee house, originally designed to house 30 single-comb top-bar observation hives. This way I can begin confronting the bee management for these different hives, although the bee house was not designed to take these large hives. The first thing I needed was additional entrance holes in the walls. I could not use the ones for the single-comb top-bar hives. They were too small and in the wrong places.

These large observation hives are three frames wide. Some take medium frames in four tiers. These hives hold a total of 12 frames (three wide times four tall). A colony of maximal size in this hive would fill a medium super (with two frames remaining).

Other hives take deep frames in three tiers. These hives have a total of nine frames (three wide times three tall). A colony of maximal size in this hive would almost fill a single-story 10-frame hive. Figure 1 shows the hives.

These frame hives are also configured in the typical vertical tiers of outdoor hives in full-size apiaries. Frames in vertical tiers allow research projects in situations more like working an outdoor apiary. As we will see, these observation hives can also provide educational opportunities, helping beekeepers to understand bee management in novel ways, by seeing a deep cross section of the combs down to the hive floor, a view not easily witnessed in routine apiary work, when working from the top of the hive.

Figure 2 shows the large observation hives from the previous fall. While the clusters will be larger than those in the single-comb top-bar observation hives, which needed considerable insulation for the winter, I still wanted the most insulation as reasonably possible on the large observation hives. I began with custom-cut heavy-duty space blankets that draped over each hive, covering their sides. Each hive has a pair of ventilation holes in the top. I cut the space blanket to keep the ventilation holes open (see Figure 3). The space blanket and the thin panel door might suffice for winter insulation except during bitter cold spells. I expect roughly two or three of those cold periods lasting for a few days every winter. Although relatively brief, those times of bitter cold cause severe bee losses with the small clusters in the single-comb hives.

For these small colonies, the 2-inch insulation boards on the sides of the hives were my next attempt at trying to survive the bees through the winter (with marginal results). In a wider hive with bigger clusters, I figured the bees would survive better. Added to that, the 2-inch insulation might be more beneficial. Cutting the boards with limited tools was a problem.

For the observation top-bar hives, the 2-inch-thick “panels,” a little larger than a deep frame, were difficult to cut from the large 4-by-8-foot sheets. After rejecting my tools that could serve as efficient cutters, I settled on a large pizza wheel to start the cut and a bread knife to finish the separation. Although my tool search had ventured into another venue (not my own), thinking of all the cutting to come, I decided to do the remaining cutting with the circular saw. I had rejected that idea earlier because of the bits of insulation it would produce. Figures 4 and 5 show how I used the tailgate of the bee truck to support cutting the large sheets into smaller pieces.

Figure 6 shows the thick insulation panels on the large observation hives. I had to give up knowing the precise winter cluster locations because these panels blur the heat leaving the hive. A comparison of the next two photographs shows this smearing effect of the heat. In the previous November (2022), Figure 7 shows three of the hives when they had only a single layer of a space blanket and the thin wooden door panels. Two of the clusters are down in the combs, typical positions for the fall. One cluster is at the very top of the hive. Depending on the severity of the winter, this position is detrimental so close to the start of winter. (The winter was mild, and the colony survived.)

Figure 8 shows a colony in late winter with the 2-inch insulation panels. Without disturbing the bees, we can determine the cluster is high up in the hive. In addition, even though the ambient temperature was around 48˚F (chilly), the cluster seems quite large. (More on this colony below.)

Now let’s see how these large observation hives can enhance our understanding of colony management using the spring technique of reversing hive bodies as an example. In the typical scenario, the winter cluster forms low in the hive, essentially at the colony’s former brood nest. Except in the South, bees cease brood rearing in late fall, a condition called brood pause. In my location, the mid-Atlantic of eastern Virginia, I can find small patches of brood by Christmas/New Year’s, showing the bees have restarted brood rearing long before spring. Clusters usually ascend over the winter, even as they rear brood, although other colonies remain low in the hive and survive just fine.

In the apiary during early spring (sometimes a little later), removing a hive cover, suddenly a beekeeper confronts irritated bees from a cluster crowded against the top of the hive (Figure 9, left). Cracking apart the hive bodies, proceeding downward, finds one of the separations devoid of bees (Figure 9, right). Most likely, all the combs below this separation lack bees tending them. Moreover, the cells are probably empty, although pollen and honey could be in the combs toward the sides.

To keep the colony growing upwards, the beekeeper “reverses the hive bodies.” The hive bodies with bees, as an intact group, go to the lower position (on the bottom board). The empty bodies are placed on the ones with bees. Later in the spring, when the brood nest has expanded well into the upper hive bodies (which could be a pair of medium supers or one deep super), the beekeeper reverses the hive bodies again to their original (high/low) position. That movement will restore the deep frames under the medium frames. With hives in double deeps or all medium frames, I sometime skip the final reversal if the disturbance would be more detrimental than the management benefit.

Reversing hive bodies is a swarm prevention technique, when the colony has not shown any obvious indications of swarming. The technique helps to keep the colony from becoming crowded, and away from the swarming option.

Swarm control methods are taken to interrupt a colony already showing definite symptoms of swarming, numerous queen cells with older larvae being the most useful one. Removing queen cells (called swarm cells) is a swarm control method, along with splitting out a nuc with disproportionately more adult bees compared to the combs removed.

In the apiary with a colony occupying the upper part of the hive, the cover just removed, I gauge the strength of the cluster, and part the hive bodies, starting where I figure the expanded cluster has ended just above. In the numerous descriptions of reversing should come the warning about not breaking the cluster, moving a small part of the bottom of the cluster (in the upper part of the lower hive body) up to right under the cover. Besides damaging the overall coherent strength of the cluster, a spring cold snap could damage the upper cluster fragment badly, depending on the severity and duration of the inclement weather. Separated by empty comb (a cold barrier), the bees in the upper cluster fragment are not expected move down and join the larger cluster below, comprising the brood nest. That is not how a cluster forms when the temperature decreases. Rather, the exterior bees move toward the (local) warmer inner region of the cluster, resulting in a large main cluster below and a small fragment above. (We will see another version of this situation below.)

In the bee house, the large observation hives easily show the need for reversing. For hives managed in all mediums, Figure 10 shows the large observation hive and its counterpart in the apiary. Working among the hives, ….