Honey Bee Medicine for the Veterinary Practitioner. Группа авторов
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resulting in injury to the queen (Figure 5.23). Or, a queen will occasionally drop off a frame to the ground, unnoticed, or sometimes even fly away (although she usually returns).
Practical application: a vet not highly practiced at handling frames of bees may wish to have the hive owner pull any frames for inspection, in order to avoid be blamed for killing the queen (Figure 5.23).
The colony does have a trick up its sleeve, however, to replace an unexpectedly lost queen: within hours it will begin making postconstructed “emergency queen cells.” All female larvae are totipotent (capable of developing into either caste) until they begin differentiating due to their dietary change beginning roughly 24 hours into their development.
Figure 5.23 The author has too many times observed a novice beekeeper inadvertently injuring a colony's queen, only to later see her body having been drug out the entrance. After any colony inspection, always check the ground and sides of the hive for small clusters of bees that may contain a queen.
Figure 5.24 Typical emergency queen cells at about a day after initiation, showing the process of floating worker larvae to the top of their horizontal cell on surplus jelly, and then adding additional wax to turn what is now a queen cell vertically downwards.
Practical application: Should a queen be unexpectedly lost, the workers have only a few days to save the colony – by converting at least one worker cell containing a female larva less than 24 hours old into an “emergency queen cell” (a “postconstructed” queen cell). This is done by floating chosen 1st‐instar larvae to the top of their cell on jelly, and then building a vertical queen cell downward (Figure 5.24).
Identification of emergency cells: The scattered appearance and multiple number of the above emergency cells, surrounded by cells of equal‐aged young larvae (not visible in this view) identifies them as emergency, rather than swarm or supersedure cells. These cells are only just started and will soon look similar to a supersedure or swarm cell. Before their emergence, however, the bees will cull some emergency cells, leaving only those with the best queens to emerge (Punnett and Winston 1983).
Practical application: The process of replacing a queen takes time. The first queens won't emerge until at least 12 days, then a virgin needs a few days to mature enough to take a mating flight (weather permitting), and then develop her ovaries prior to commencing egg laying (which typically commences 10–14 days after her emergence). Thus, it takes around 25–30 days after losing its queen before the colony will again exhibit a laying queen.
“Laying Worker” and “Hopelessly Queenless” Colonies
Should a colony be unsuccessful at producing at least one successfully mated replacement queen, it will become “hopelessly queenless.” Without a queen's (and perhaps the brood's) pheromones suppressing ovary development in the workers, some workers will then commence to lay eggs, and are called “laying workers.” Unfortunately, those eggs, being unfertilized, can develop only into drones (Figure 5.25).
Figure 5.25 Typical eggs from laying workers. Unlike those laid by a queen (singly and upright in the center of each cell), laying workers often place several eggs in a cell, not centered, and sometimes on the cell wall. Compare this egg pattern to that in Figure 5.7.
Practical application: Signs of laying workers normally don't appear until around three weeks after the loss of the queen.
A laying worker hive can survive for quite some time, but tends to become “pissy” and full of undersized drones.
Practical application: Once a colony goes “laying worker,” it is difficult to requeen. Although there are any number of “folk remedies” for requeening a laying worker colony, it is generally easiest to temporarily combine it with a queenright hive, wait a few days for that queen's pheromones to again suppress the ovaries of the laying workers, and then to split the combined hive, giving the queenless portion frames of brood and an introduced queen or a queen cell.
Queen Status Assessment
Beginning beekeepers often wonder whether their colony has “gone queenless,” or if their queen if “failing.” The vet should be able to address these questions. The vet's first assessment would be to determine whether the colony is:
“Queenright” – containing a functioning, laying queen,
“Queenless” – with perhaps a queen in the works, or
“Hopelessly queenless” – meaning that the colony has not only lost its queen but has passed the window of opportunity to replace her. A colony at this stage often exhibits the signs of having gone “laying worker.”
Signs of Queenrightness, Failing Queens, and Queenlessness
It is generally much easier to find signs of a queen than to spot the queen herself, and in most cases there is no need to actually see the queen. If there are eggs and larvae present, that usually indicates that the colony is queenright, especially if the egg pattern is as below (Figure 5.26).
Scattered Drone Cells
Queens do “age,” and in the process may exhibit poor brood patterns, suggesting that they be replaced. In general, few queens are good for more than a year and a half of egg‐laying, by which time their spermatheca simply runs out of viable sperm. At that point some eggs laid in worker cells will develop into drones (Figure 5.27).
The workers apparently cue on unfertilized eggs as a signal that the queen is failing and will usually supersede a queen before this becomes noticeable, but if they wait too long, they may not have any female larvae from which to raise a replacement queen.
Figure 5.26 A nice egg‐laying pattern by a queen – each egg centered in its cell, with no misses. The eggs are glued upright and typically slightly tilted (often the eggs are all tilted in the same direction). A pattern such as this indicates a high‐quality