The Role of Nurse Bees in the Hive
A family of honey bees is composed of thousands of individuals. Each colony member has a task to perform in support of the hive. You may be surprised to know that female workers go through an array of jobs during their short lives. But, it is the role as nurse bees that is most critical to the next generation of bees.
Honey Bee Nurses
Honey bees are social insects that work together for the benefit of the colony. When you look at the different jobs a worker bee, it is easy to see that she is quite remarkable.
These ladies develop a wide range of skills. And, the anatomy of honey bees provides special structures to help her get the job done.
The actual time number of days spent at each type of task varies a bit due to hive genetics (genes) and the needs of the colony. We can state generalities but in a normal hive – there is no hard and fast rule regarding when a bee does a certain job.
In general, young adults perform work inside the hive (brood care, comb building etc.) and older workers transition to outside jobs. They become guards, foragers and field bees
These changes in behavior are supported by physiological factors. Young adults normally function as nurse bees.
Their primary job is the feeding of young brood. Special glands in the head and mouth are well developed to produce the nutritious food needed by growing bee larvae.
As the worker ages a bit, her wax glands and alarm pheromone glands mature. This is preparing her for her role as a comb builder, a guard bee, forager and even a scout bee.
Nurse bees have a stinger and can sting but they do not normally need to – it is not their job. Bee stings are reserved for hive defense and that is the job of older workers.
Juvenile Hormone
How do nurse bees changed into other functions? Without getting into a deep scientific discussion, one factor that affects these changes is a hormone. It is called juvenile hormone (or JH). Contrary to what the name may imply, it is a maturing hormone.
Young adults have low levels of JH. As bee ages, her duties as nurse bee transitions to different tasks. And, her JH levels increase.
Prime Nurse Bee Tasks
In the typical, healthy hive, newly emerged bees begin their tasks as nurse bees on about day 3. Responsible for brood care, their brood food glands (hypopharyngeal and mandibular) are mature enough to function.
A colony of honey bees uses pheromones to communicate. Nurse bees are attracted to young by the pheromones given off by larvae.
At the cell, the nurse bees secrete tiny white drops of brood food into the cell. Older honey bee larvae may be fed bits of bee bread.
Larvae have a voracious appetite. On average, a nurse bee will visit each cell over 3,000 times during the period of larval development.
The amount of time spent as each cell varies – some only require a quick check. Once it is time to transition into a pupae, feeding is no longer needed.
In the brood nest, developing workers and drone larvae are fed similar food – including royal jelly. But, female larvae that are intended to be queens are fed larger amounts of food of a different composition.
Transmission of Disease
As important as the role of nurse bees are, they can also be responsible for harm. Disease is often spread to brood during feeding. European Foulbrood is one example.
The bacteria that cause this disease persists on cells walls, feces and wax debris. Sometimes, the nurse bees are exposed and feed contaminate food to healthy brood.
Needs of the Colony Affect Job Transition
A remarkable ability of a honey bee colony is the manner in which they can change direction when needed. If the queen bee dies, in most cases, the hive can produce a new queen.
The same situation applies to roles of the bees in the hive. In natural age progression, nurse bees go on to become wax builders, guards and eventually foragers. However, they are capable of changing their job description much sooner.
Imagine a hive with a good population of forager bees collecting the resources needed by the colony. Then, a horrible thing happens – many of the foragers die (perhaps due to poisoning, exposure to pesticides or other catastrophes.)
Now, many of the nurse bees in the brood region have no new food coming in. They will quickly transition to foraging activity.
This is not an ideal situation and may result in a loss of some brood. Or perhaps, the developing young will not be fed properly due to a lack of staff.
However, the colony must have pollen and nectar coming in to feed the remaining nurse bees and young. About 10% of foragers die each day through normal aging. When a special hardship hits, the colony must adjust.
It is also believed that the earlier bees start foraging, the faster they age. Therefore, in a colony where nurse bees are accelerated to foraging sooner than normal – those foragers will not live as long.
Colony Stress Due to Lack of Nurse Bees
Due to the important task of feeding growing brood, the hive must have enough nurse bees to do the job well. Larva deprived to sufficient nourishment will not be as strong and healthy as those that are well fed.
This also applies to queen production. Queen cells in a colony that lacks a strong population of nurses and food resources tend to be smaller.
Not an ideal situation for a hive that is producing a future queen. A healthy good-sized queen bee is more likely to be a productive layer of eggs.
As beekeepers, we must remember the importance of having balanced hive populations. Avoid splitting hives into too many parts unless you have the population to support it.
Feeding small colonies that are busy growing helps relieve some of the pressure of bringing in food. This is often true for new colonies started from package bees or small swarms.
Each job in the colony is important. The different types of bees in the hive all have a part to play. In nature, this generally works out well and results in productive hives. As beekeepers, we must strive to help (but not too much) without hindering the progress of the bees.