BEE BIOLOGY
By Chari Elam
Thanks to a reader request bee biology is back in the lineup. For those who don’t know our story, James and I were two of the lucky few who were gifted our first bees. We were diligent about attending bee club meetings and paying very close attention to our mentor. But one thing we didn’t grasp was the importance of truly understanding the life cycle of our bees. So much so we killed our first hive—dead. And I do mean dead! What did we miss? Just about everything relating to what should be happening, when it should be happening and who is supposed to be doing it. These three aspects in essence killed us! We misinterpreted what we saw or more to the point what we didn’t see. I want to save you that grief because boy oh boy losing that hive was sad. It could have easily driven us to give up. Hmm that’s an interesting thought when looking at where we are now.
Queen
Within the caste system we see that a queen is basically an overfed worker. The big difference is that her food source is exclusively royal jelly as opposed to bee bread. Royal jelly is what produces the growth of this sexually mature female’s reproductive organs. Conversely bee bread inhibits it. A queen is fertilized in flight and will take multiple flights to become fully mated. Once mated she will never mate again.
The queen ensures her hierarchy by way of pheromones. QMP (queen mandibular pheromone) primarily assures the colony that she is there and doing her job of laying eggs. If the colony doesn’t detect QMP a replacement queen is soon generated. In order for this to occur a one(ish)-day-old larva is chosen by the worker bees and they either move it into a queen cup or quickly build a queen cell around it. Within the next 16 days a new “replacement” virgin queen will (in theory) emerge, mate and carry on! For a beekeeper this would most likely be the moment in which a purchased-quality breed queen would either precede or follow this process in order to control the genetics of the hive.
Laying Eggs
A honeybee queen has the unique ability to lay a fertilized or an unfertilized egg at will. This is specifically determined by the size of the cell with which she is presented. If the cell is worker size (4.62 mm–5.51 mm) she will lay an egg and then immediately release a sperm with it. If the cell is larger (6.15 mm–6.91 mm) she will lay an egg but withhold sperm.
This is significant in that the fertilized egg will generate a sexually immature female (worker bee) and the unfertilized egg will generate a sexually mature male (drone)! So incredibly interesting! In her egg-laying lifetime she will lay upwards of 2000 eggs per day each spring and summer and do so until she runs out of sperm (could be as soon as two years depending on the quality of her mating).
This tells us that the queen is not in charge; instead the workers building the cells are! Their road map to cell sizing is directly associated with the season and food availability. The ability for a worker to prepare nature for the perpetuation of the species is nothing shy of miraculous.
Watch as the queen lays eggs. Each time she pulls out of a cell she measures the next open cell with her antenna and mandibles determining whether or not the egg she lays is to be fertilized or not.
The Worker Bee
This sexually immature female bee is the true lifeblood of a colony. Without workers from across the full scope of age groups a colony can cease even with a viable queen. That’s a lot riding on these tiny shoulders! They are equipped with the following abilities:
- Nurse bees: Feed brood food [mandibular gland secretions, hypopharyngeal gland secretions(royal jelly) and protein-rich pollen in a 2:9:3 ratio = bee bread]. This process is done from day four to day nine of development. These six days of being fed are critical for developing viable brood. In the event that larvae are improperly fed, inferior bees will be bred—meaning bees with poor foraging ability, shorter life spans and an overall inability to support the colony. Egg 3 days + larva 6 days + capped with wax at day 9 = emerge at day 21. Nurse bees also feed and groom the queen (retinue), clean cells and warm the brood nest.
Definition of bee bread: The fermentation of bee pollen mixed with bee saliva and flower nectar inside the honeycomb cells of a hive.
Bee bread By Nanette Davis
- Wax glands: Produce wax to build comb. This is typically the 11- to 18-day-old worker bee. It takes a continual feeding of nectar for wax glands to produce. Any interruption of consumption can interrupt this process and cause a lag in drawing comb.
- Foraging and transporting pollen and nectar: Honey bees gather pollen by being led to a plant or flower with nectar. Static electricity generated from flight and a bee’s wings flapping 11400 times per minute attract dry pollen from these plants to the bee’s hairy body (scopa). It is then combed from the body with the bee’s front and middle legs and put onto the back legs, which contain a pollen basket (corbiculae). This basket is what enables the bee to transport the pollen back to the hive. The pollen is then deposited into a cell. Nectar gathering is done most often at the same time that pollen is gathered. A honeybee uses her tongue (proboscis basically a straw) to draw in nectar and then stores it in her honey stomach for transport back to the hive. Nectar is then handed off to a receiving bee and placed into a cell, ultimately becoming honey.
- Propolis: For health and hive protection, propolis (a sticky resin gathered from plants and trees) is acquired much like pollen is. It is transported by way of pollen baskets and returned to the hive to be utilized for sealing cracks and crevices as well as stored in various places in the hive for future use. It is well documented that hives with heavy propolis-storing traits are healthier.
- Thermoregulating the hive: Temperature regulation is a very important aspect of colony health and success. Worker bees have the ability to uncouple their four wings, allowing them to fan a hive’s interior to regulate not only the temperature but also the humidity. A brood nest is required to maintain 93–95 degrees to grow viable brood.
What a huge responsibility! Absolutely everything that supports a colony’s health (other than laying eggs) rides on the backs of these industrious workers.
Au contraire—they can lay eggs! If QMP is absent from a colony for three weeks (1 brood cycle) then in a desperate attempt to save the colony not just one but many workers will begin laying eggs. “But wait,” you say, “they aren’t mated!” Yes, that’s correct and because of that they will lay only unfertilized eggs which we now know are drones. A colony cannot survive on drones alone therefore a colony with laying workers is doomed to die in most cases. See “Attempting to Save a Drone Layer Colony.”
Chart of Temporal Polyethism:
Age-Related Division of Labor As seen in this chart, bees’ duties are age specific. The absence of one of these age groups could very well cause havoc in a colony. But wait, can an older bee revert to doing a younger bee’s tasks? It can! In the instance of a void, worker bees’ plasticity allows them to fill in, moving either up or down in the age-related duties. Unfortunately, this doesn’t always happen. More than likely, this is dependent on the time of year: winter bees are more likely to revert to spring duties than spring/summer bees in the same season.
The inability to complete a task in the hive brings us full circle in knowing the importance of bee biology. As beekeepers this is where we can step in and solve a problem nature can’t. Recognizing a lag in honey production in spring suggests a low-forage population. No wax being built indicates a lack of 11–18-day-old worker bees. You get the point.
Solving problems like these is easy when you have more than one colony and a clear understanding of the life cycle and biology of the bee. Trading brood, honey, or pollen frames from hive to hive can completely reverse the decline that is no doubt imminent otherwise.
Drones
Even though they are often given a pat on the back for the ability to be lazy and get by with it, drones are the only reason the species is able to propagate. Yes, they die after mating. And given the magnitude of that role, it does seem a bit unfair! Drones rarely feed themselves and don’t do any gathering of resources or tend to the hive in any way whatsoever. Therefore, in the fall, workers kick them out to rid the burden of overwintering with the overeating hive occupant. It’s not at all uncommon to see drones still present in southern states. In such cases, they are beneficial to warming the winter hive when given the opportunity. A drone is a larger bee (larger cell) and has a 24-day egg-to-emergence time frame, making drone brood an ideal breeding ground for Varroa mites due to the “extended-stay hotel” they use.
What a wonderful, intricate little creature our little honeybee is.