Colony usurpation is when a summer swarm takes over an established colony by quickly invading it in a matter of minutes. While some of the hive bees and the usurpation bees fight, the crucial action is with the queens. The usurpation queen becomes balled near the hive entrance, where she just entered with the invading swarm. Deep in the brood nest, a ball of worker bees also forms around the mother queen. (The origin of the bees in these balls is not well known.)
Queen balling is where bees form a tight ball about the size of a walnut around a queen. The behavior is poorly understood. Generally however, queen balling can result in the death or damage to a queen. The hostile treatment should be avoided in normal beekeeping. On the other hand, apparently queen balling can be a mechanism to protect a queen in uncommon situations.
In as quickly as 13 hours, the bees can release the usurpation queen as the accepted queen of the colony. (That is much faster than beekeepers can typically introduce a new queen.) In an observation hive, I have seen the usurpation queen lay eggs in the brood nest of the mother queen while she was still in a ball–destined to die. As the carrier of all the genes of a colony, this rapid queen replacement is stunning. From a beekeeper’s perspective, “it’s out with your queen, in with some unknown queen.”
The usurpation behavior is also relatively new. Now I routinely see what I term “summer swarms” reserving the term “usurpation swarm,” for when a summer swarm engages in an actual colony invasion. For me, the difficulty is catching the swarm in the act of invading a colony. In the December 2010 American Bee Journal, I published photographs of usurpation bees dashing in a hive. Subsequent usurpation articles and photographs followed. Although I think usurpation occurs frequently in the summer, I have wanted to see another invasion occur. I have had some close encounters–until this past summer.
Except for presentations at bee meetings, I avoid taking trips in my busy spring season with swarming and checking my numerous bait hives. Summer season is my “usurpation season,” and I still should be near my bees. My main book-writing season is during cold weather when the bees need less attention, except for patrolling apiaries and data collecting with thermal cameras. Therefore most of the year, I am near my bees.
The summer of 2017 was different because of a coming rare celestial sign, which said, “leave your bees.” It was a solar eclipse over the continental United States on August 21. Breaking my pattern, I would travel away from my bees for just two days. Suzanne and I traveled from Virginia to South Carolina to be in the shadow of the full eclipse.
On the morning of August 20, right before we departed, I checked my research bees around the bee house one last time. What I saw is in Figure 1. The pipe to one of my big observation hive colonies is at the upper right. At the lower left, under the cross supports of the adjacent door, is a summer swarm, a potential usurpation swarm. First seen right when I’m leaving. What timing!
The solar eclipse would not wait, but we had to delay leaving for a little while. When a potential usurpation swarm lands under the hive entrance, they could remain there for days and possibly invade the colony or fly off. I try to learn something from every potential usurpation swarm encounter, so I ran to the house and grabbed my camera equipment.
The morning was cool and I took a series of photographs in visible light and in short movie clips. Next I took thermal photographs and videos too, the first time I had such technology close-up with one of these mysterious swarms. Even in the coolness, a few bees were leaving and returning from only the bottom of the swarm. The remaining bees were relatively calm. These returning bees waggle-danced at the bottom of the cluster. Sometimes they danced on other bees or on the wood substrate.
One must keep in mind this swarm does not necessarily behave like a reproductive spring swarm. Those dancers were not scout bees out nest-site hunting. This swarm was not looking for some hollow tree to live in. Put this swarm in a nuc box with drawn comb, and they probably would not stay, as perplexed beekeepers have tried.
These dancers had been out foraging and were bringing in morning nectar. I have observed this foraging behavior numerous times with other summer swarms found near my apiaries. During or after the dancing, the forager unloads her nectar to other bees, sometimes three at once. This behavior is easier to observe with a very small swarm, one layer of clustered bees, and when demand for food is large.
As far as I know, in a temperate US climate with the “old bee genome” before 1922, a reproductive spring swarm does not send out foragers to feed its masses of bees, most of whom were fully engorged on honey when they left the parent colony. Rather their nest site selection process is for the scout bees to rapidly reach consensus on …
