Honey Bee Medicine for the Veterinary Practitioner. Группа авторов

A typical supersedure cell. Supersedure cells are generally found singly, as opposed to swarm or emergency cells, of which there are generally several. They are also generally found near the center of the brood area, rather than along the edges, as are swarm cells, or scattered, as are emergency cells.

Figure 5.11 A dissected supersedure cell after emergence, showing that the egg had been laid in a preconstructed cell cup (as for a swarm cell), as opposed to the cell being postconstructed from a worker cell (as for an emergency cell). We are not yet clear as to the proportion of supersedure cells that are produced by these two different routes. There is also some evidence that workers may be able to transfer an egg or young larva from a worker cell to a queen cup (Punnett and Winston 1983).

Not all supersedure cells come from prepared cell cups. Some that I have dissected originated from worker cells (Figure 5.11), so the line between supersedure and emergency cells may be fuzzy.

Figure 5.12 Two laying queens on the same comb face (the lower one is a bit above the finger). On the other hand, I occasionally see a failing queen being “balled,” suggesting that her own workers are killing her.

Although sister queens will invariably fight to the death, an emerged daughter queen and her mother often peacefully coexist.⁵ It is not uncommon to observe mother and daughter laying eggs side by side for days or weeks, with the mother eventually disappearing from the hive (Figure 5.12).

Practical application: Although it is generally the case, never assume that there is only a single queen in a hive. The only way to be sure that all queens have been removed is to shake the bees through an excluder “sieve box” (Figures 5.13and 5.14).

      “Balling” of the Queen

In the process of supersedure, the workers often show no mercy toward a no‐longer‐wanted queen. Bees kill a queen in the same way that they kill invading hornets, by biting her and forming a tight, heads‐in, walnut‐sized ball of bees around her (Figure 5.15). The bees then produce heat and direct it to their heads to “cook” the queen. Thus, even if one manages to “save” a queen being seriously balled, she rarely survives.

Practical application: There is great demand for “early mated” queens. But the weather does not necessarily cooperate, resulting in a percentage of early queens being poorly mated. And during shipping, temperature stress can cause loss of viability of the spermatozoa. Whatever the reason, many beekeepers report that newly‐introduced, or package bee queens, get superseded within the first month (this is not necessarily a problem).

Figure 5.13 Shaking bees through a sieve box to recover any queens. This is important when setting up a cell‐builder colony, as above, in order to mass‐produce emergency queens from selected mothers.

Figure 5.14 The thorax of a queen (center) or drone (lower right) is too broad to pass through a queen excluder.

      Queen “Failure”

      “Queen failure” is a nebulous and poorly‐defined term, nowadays given in surveys as a choice for the cause of colony mortality. As such, it is often listed as the most common cause of colony loss by beekeepers (BIP 2019). This is somewhat surprising, since “back in the day,” colonies tended to quietly and efficiently replace their queens via supersedure without any help from the beekeeper, and when I review older beekeeping textbooks, the term “queen failure” isn't mentioned.

Figure 5.15 This aged queen (note the well‐polished thorax) became a “drone layer.” This photo shows her workers aggressively attempting to “ball” her to kill her.

      Practical application: Infection by Nosema apis used to be strongly associated with early queen supersedure (Farrar 1947), but this does not appear to be the case with N. ceranae, which has largely supplanted its cousin. Thus, treatment with fumagillin against nosema may no longer be necessary to protect queens.

      Since the arrival of varroa, the stress from greater virus exposure, as well as miticide residues in the combs may be having adverse effects upon queen survival. Similarly, residues of some agricultural insecticides may affect queen longevity.

       Practical application: The question may be, why aren't colonies simply superseding failing queens, which would prevent a “colony loss.” I wonder whether what we are now seeing is more “unsuccessful supersedure” rather than “queen failure.” Some possible suspects would be genetics, pesticide residues, miticide residues, or something to do with varroa and its associated viruses.

      Swarming

      Given the right conditions (especially in springtime), a colony will typically divide itself and swarm, taking the old queen with them, and leaving behind “swarm cells” containing replacement daughters about to emerge.

Practical application: It is normal for a colony to reproduce by swarming once it's filled its cavity (whether a tree hollow or a hive). This normally occurs during the local “swarm season,” and especially with queens that are over a year old. Some swarming may also occur in crowded colonies later in the season.

      One can generally tell whether a colony is preparing to swarm by tipping up the brood chamber (or upper brood box in a double). Most (but not all) swarm cells will be built along the bottom bars of those brood frames (Figures ).

       Practical application: Queen cells are easily damaged if one attempts to cut them from a wooden frame. But frames containing queen cells can be carefully moved to a split.

Figure 5.16 Typical queen cells, some sealed, some in development, along the bottom bars of an upper brood chamber. This colony could be split, with each portion receiving at least one frame with a queen cell.