This is a revision post for the BBKA Module 6 Honeybee Behaviour exam. I’m trying to work my way through the syllabus, one section at a time. Starting at the beginning:
6.1 The candidate shall be able to give a detailed account of: the function and behaviour of the worker honeybee throughout its life including the types of work done, duration of work periods under normal circumstances and the variations in behaviour due to seasonal changes in the size of the colony.
When a worker bee emerges, all soft and fuzzy, one of her main priorities will be eating pollen from nearby cells. The protein in pollen is important for developing her hypopharyngeal (they don’t make these names easy) & mandibular glands, which will produce brood food and royal jelly, as well as her wax glands. Between pollen eating she will help out the colony by beginning in days 1-3 with the simple tasks of cleaning the cell she emerged from and those around it (which takes hive-proud bees longer than you might imagine – about 41 minutes a cell, with about 15-30 worker bees helping out) and, if necessary, brood incubation by sitting on top of capped brood cells.
Bees hanging out on a comb.
About days 4- 6 she will progress to becoming a Nurse bee, feeding young larvae with the brood food secreted from her glands and older larvae with additional honey & pollen. If it is swarm season, or the bees decide to supersede the existing queen, she may be helping raise queen larvae, which will receive large amounts of protein-rich royal jelly.
By around 10-12 days old her wax glands will have developed and she can begin wax making, along with processing honey into nectar, pollen packing and temperature control duties such as fanning in hot weather. She may also be an undertaker bee, removing dead bees and other debris from the hive. By days 16-20 her hypopharyngeal gland decreases in size and begins producing invertaze and glucose oxidase, enzymes required for honey production. Her body is getting ready to forage.
Bees on a frame of pollen.
Out and about
Our bee has progressed from spending most of her time in the centre of the brood nest to moving further out on the comb for wax building and food handling duties. She will spend days 19-21 on the edge of the nest, fanning or guarding the entrance and making longer orientation flights than previously – she has become an outside bee. Her body is now able to produce the alarm (2-heptanone) & sting (isopentyl acetate) pheromones, along with venom.
She will spend the rest of her life – about another 20 days – foraging for nectar, pollen, water and propolis. The flight distance she accumulates rather than her chronological age seems to do her in, since workers tend to die after flying a total of about 800 km, whether that distance was flown in 5 days or 30. This appears to be caused by exhaustion of the necessary glycogen reserves which accumulate in the flight muscles of young workers; older foragers are unable to produce more glycogen and die of exhaustion.
But bees are very flexible…
Despite the rough time frames given above, the activities a bee carries out are extremely variable and flexible depending on factors such as colony population or the time of year, for example in spring as the colony expands foraged food is mainly eaten by the brood and little honey is stored. If a lot of nectar is being foraged by outside bees, house bees will be encouraged to become receivers and honey makers earlier. However, certain duties such as wax making and entrance guarding are dependent on gland development.
Despite their reputation for being ‘busy bees’ workers often spend a lot of the time resting or walking around the colony, allowing them to react quickly to emergencies or an increase in nectar/pollen flow. Resting or alternating tasks also allows their body time to recover, for example for the wax glands to produce more wax before a bee returns to comb building or for the hypopharyngeal glands and mandibular glands to produce more brood food.
The tasks described above are the life of a spring/summer worker bee. Autumn bees that do not raise young live longer, as the pollen they eat is not used for brood food production but instead increases their body’s fat content, which helps them to live longer as they over-winter. When the temperature falls to about 18C they begin to cluster around the Queen with their heads inwards, contracting the cluster as the temperature drops. They consume honey and shiver their flight muscles in the thorax to generate heat. Once the weather warms and the queen starts to lay eggs again they will begin nursing brood and foraging.
More revision/Module 6 themed posts:
- 2nd Honey bee behaviour revision post: honey bee mating
- 3rd Honey bee behaviour revision post: the queen’s egg laying behaviour and seasonal variations in the size of a colony
- 4th Honey bee behaviour revision post: social organisation of the colony
- 5th Honey bee behaviour revision post: bee communication
- 6th Honey bee behaviour revision post: bee foraging
- Passed 🙂
- BBKA exam feedback