In the previous article, we witnessed a usurpation swarm nearly take over a frame hive. Here is another near takeover. I also include the events that would have happened in replacing the colony’s queen (called the resident queen) with the usurpation queen. (The colony being taken over is called the host colony.)
The usurpation swarm lands near the entrance the way we saw in the previous article. The entrance configuration may force the swarm to enter the host hive without the bees first gathering for a mass rush through the entrance. In my bee house that houses 30 single-comb observation hives, I sometimes have an extra observation hive with multiple combs. The hive has an entrance on the vertical wall with only a small alighting board. When a usurpation swarm tried to invade this hive, the bees encountered various obstacles.
The usurpation swarm had difficulty landing on the vertical wall, and the small alighting board was of little use (see Figure 1). Next the usurpation bees had to run down a fairly long entrance pipe before reaching the brood nest. I do not think the bees ever balled the resident queen in the brood nest, which apparently happens when the usurpation bees first invade the hive. The usurpation never progressed that far. In this case however, under the entrance, I found a dead queen, which turned out to be the usurpation queen. She must have been stung during the initial invasion.
What should have happened, from what I have observed from seeing several takeovers, is the usurpation queen enters the hive among the swarm. She is quickly balled, most likely by usurpation bees for her protection. I expect this ball with the usurpation queen to be on the hive floor, somewhat near the entrance. Early in the invasion, another queen ball occurs too, deeper in the brood nest. This ball contains the resident queen. From within the host brood nest, this ball may slowly descend between the combs down to the hive floor, if it does not become hung up somewhere along the way. (If the queen ball with the resident queen reaches the hive floor, it could be confused with the queen ball containing the usurpation queen, although the usurpation queen ball should not last too long.
At around 12 hours or so the bees release the usurpation queen. Apparently, the pheromones from her have changed, making her very attractive (or the queen-recognition threshold among the bees has decreased). A super-court of bees forms around the usurpation queen (see Figures 2 and 3). While currently the origin of the bees in the court remains unknown, it suggests the takeover could have a chemical component, as observed in the usurpation with other social insects (Lenoir et al., 2001).
When I see the super-court formation, I know that usurpation queen has been accepted as the new queen of the colony, even though the resident queen remains in a ball. At this point in the takeover process, the resident queen is doomed. A couple days later, she dies, maybe from the stress and slow starvation in the ball, although not apparently from being stung.
Here is the devastatingly important point: In less than a day, the queen and all the genetic characteristics that originate from her have changed to the usurpation queen (which as far as I have seen are mated queens).
If the beekeeper meant to maintain a particular bee stock in the host colony, the usurpation swarm destroyed that configuration, but of course not the life of the colony. Moreover, the time for the swarm to enter the hive is usually brief, around 20-30 minutes, leaving some straggling bees standing around the entrance, in addition to the resident bees. While the bees of the usurpation swarm and host colony fight, the dead and dying are evicted from the hive. They may not be noticed in tall grass or if removed by scavengers. Taken all together the usurpation process is subtle, and it occurs fairly quickly, unless something stalls or blocks it.
One apparent disruption to a smooth initial part of the takeover could occur when the usurpation queen becomes balled before entering the host hive. (If the usurpation ball does not form in the host hive, the ball around the resident queen, if it forms, will not persist, as seen in my observation hives.) First, I am assuming that when nearing the time to invade the host hive, the usurpation swarm is primed and ready to ball its queen (for protection). Encountering too many foreign bees, as inside the host hive (probably with alarm pheromones), could cause the usurpation bees to ball their usurpation queen, the ball found on the hive floor early in the normal invasion process.
If the usurpation bees ball their queen before they enter the host hive, a reasonable hypothesis is that it stalls the usurpation process (although the ball in this context may have other functions). If the usurpation bees encounter too many foreign bees (at some threshold), probably from the flying bees from the apiary (perhaps some showing aggression), in response, the usurpation bees ball their queen to protect her. In the swarm cluster, the small ball of bees is not securely attached to the adjacent festoons. I have watched them slowly descend and fall under the swarm cluster, once from an absconding swarm followed for a short distance to one of my apiaries (another small summer swarm flying to an apiary like we saw in the previous article).
In the summer of 2008, this small swarm began as a late-summer absconding swarm from a top-bar hive in one of my apiaries. I stopped the swarm from leaving its hive by using a desperate trick. I caught the queen just before she flew from the alighting board with the bees. I brought the swarm home, fed it syrup, and released the queen, which had been caged to prevent another absconding attempt. She began to lay eggs and established a little brood nest. For a while everything seemed normal (in the old sense).
Although I had the newly hived summer swarm near the back door of our house, I could not watch them constantly. Nevertheless as good fortune would have it, thirteen days after the bees first tried to abscond, I happened to be coming out the back door when I heard that distinctive hum of a swarm taking flight. I rushed over to the hive, and sure enough the bees were leaving again. The time was 5:21 p.m., again late in the day as with their previous absconding departure, which was 6:07 p.m. when I first caught them.
For this swarm flight, I decided just to watch them, with no attempt to catch the queen, thinking I might learn something new by not intruding, figuring the little swarm would likely fly over the trees, ending the lesson. Among the bees streaming out of the hive, I watched the queen emerge from an entrance. I stood motionless and just let her take flight. She slowly circled her way up into the cloud of waiting bees. As before in their first absconding, all adult bees evacuated the hive, and again they left unripe honey in about 150 (uncapped) cells (most of it sugar syrup). If the bees were absconding in response to lack of (enough) forage, leaving that much sugar energy seemed critically wasteful. Some of the bees in the swarm were engorged so they had the capacity to take that remaining syrup.
After a couple of minutes, the swarm began to move, and I followed the cloud. The swarm flew up high and headed to the woods on our property. A gentle headwind kept the swarm’s forward speed fairly slow. Keeping up was easy, at first. The swarm’s direction above a dense thicket under the trees would slow me down. Soon, I figured on losing the swarm. Upon going into the woods, I noticed the bees flew toward my bee house with observation hives for my research. I could hear the swarm above the trees. Then the swarm cloud descended through the break in the tree canopy above the bee house.
With all the tall trees nearby, the swarm could have landed well out of reach, ending further observations, but not this time. The swarm landed in a small sumac tree next to the bee house (see Figure 4). I noticed a queen ball embedded in the network of festoons, chains of bees comprising the cluster. The festoons of the swarm cluster give the general appearance of vertical lines. That structure is somewhat obscured by the bees walking on the festoons. What I noticed, first near the bottom of the cluster, was a …