What's the buzz?

Prof Robin Crewe is a senior research fellow at the University of Pretoria's Centre for the Advancement of Scholarship and he is the co-author of The Dark Side of the Hive, a book that forces us to re-examine everything we thought we knew about honey bees.

Most people have a perception that beehives and colonies are perfectly built, and that they are places of industrious labour for the greater good of the colony and a workforce working for the common good. Prof Crewe’s research uncovers the “dark” side of bees. He finds that there are lazy bees, sloppy builders, bees who are thieves, stupid bees and assassins too.

The book takes us in great detail from the earliest origins of bees and how they evolved right through to the present day and some of the challenges they face.

According to Prof Crewe, “What may look obvious from one perspective may actually not be the case. What seems plausible at first sight may turn out to be completely wrong when reconsidered. We should remember the long misconception of a honey bee king ruling the colony formalised by Aristotle in 350 BCE because he considered the sting to be a sign of the male sex and the stingless drones to be the females. For more than 1,800 years, it was common sense to have a king in the honey bee colony because who else could rule such a large community? Only after the work of Luis Mendez de Torres in 1586 and propagated in English by Charles Butler in 1609 did it become clear that the king was rather busy laying eggs and hence might be a female. This was finally confirmed in 1670 when Jan Swammerdam showed that the queen actually had ovaries and was the only fertile female in the colony. These misconceptions were just the first steps in helping us understand honey bee biology today.

“In this book, we do not argue that we are the only ones to have found the biological truth, but we attempt to draw an up-to-date picture of what individuals in a honey bee colony do to get by in their lives. In fact, sometimes it is easier to comprehend social behaviour in animal systems if we borrow terms from our own social structures. Despite all the profound differences, social systems of bees and humans often follow similar rules for problem-solving, yet those in bees stem from natural selection, whereas those of human societies primarily originate from cultural evolution. Although some mechanisms may be similar, others will be completely different, and any comparisons are only helpful if they facilitate comprehension in either system,” says Prof Crewe.

“This study was crucial because so many studies on honey bees focus on the queen. She is unique among the females, but we also tried to study the males because so little research has been done on them. Most students of honey bees focus on the female sex and see no need to study the lazy drones. And, yes, this is a gender issue in its truest sense because drones are anything but lazy, and the single-chromosome males often die without mating. Colonies themselves invest so much into their females that it compromises most of the individuals in the colony and males are only produced when there are excess resources for colony growth.

“My own interest in bees comes from a fascination with deciphering chemical communication systems that are highly developed in honey bees. The queen regulates much of the behaviour in the colony via the chemical signals that she produces, and documenting this communication system has led to a better understanding of the management of colonies for agricultural purposes.”

It is crucial for us to understand bees, and in particular honey bees, because our fate as humans and their fate as bees are inextricably intertwined. 

Watch the short video on the sidebar to learn more about where bees come from. Click on the infographic in the sidebar to find out some interesting facts about bees.

Click on the following pages to learn more about the hive, meet the who's who of the hive (including the ones with a darker side), learn how bees keep up with cleanliness, what they do in the event of a medical emergency, their feeding habits and mating habits. 

Bee Aware: A guide to who's who in the hive

Bees are social insects and everyone has a role to play in the hive. Bees are also very particular about their surroundings and keeping everything clean. 

The queen bee

The queen, or gyne, is the only fertile fertilised female in a colony.

• Laying eggs is the queen’s sole function in the hive.
• The only time she stops doing so is when she moves with a swarm to a new place.
• She only mates early in her life, over the course of two to three days, with up to 70 male drones.
• The queen is fed protein-rich food jelly throughout her life by worker bees to ensure that she can continue to lay eggs.
• She lays up to 2 000 eggs per day. During an average lifetime of four years, that adds up to 292 000 eggs.

Replacing the queen

A process of queen supersedure begins when the current queen shows signs of being less reproductive because of old age or because her stock of sperm is running low. Worker bees raise a new queen in the presence of the old one. Both can coexist in the hive until the older one dies or leaves with a group of workers in a swarm.

Worker bees

Do all worker bees work non-stop to service the hive?

No. As with humans, some are lazier than others, while some bees even cheat on the job. Studies have shown that bees can spend up to 40% of their time in a hive doing nothing. Some are purely part of a hive’s reserve force, and put to work only when there is lots of nectar to be collected and processed.

Bees are seen as master builders, able to create one perfectly shaped hexagonal cell after the other. How true is this?

Left to their own devices, they can be quite sloppy builders. They tend to construct roundish cells, sometimes with spaces in between. The heat coming off their bodies melts the wax to some extent and, when the cell walls touch, a somewhat hexagonal shape is the result.

The fixed, absolutely regulated and ordered shape of a comb is actually a function of human intervention. Beekeepers provide bees with straight parallel frames that hold a “comb foundation”; these frames consist of wax sheets where the cell pattern is perfectly embossed. This guides the comb building activities of bees.

Are all bees equally adept at learning and remembering spatial and temporal patterns and cues, such as odours and colours?

Not all bees are equally smart. Some have better memories and learning abilities, and learn faster than others. The “brighter” ones use these skills to navigate their way around a landscape while foraging. It also helps them to more effectively perform a type of dance in which they indicate the direction of a nectar-rich flower patch to other worker bees, and how far away it is. Thanks to this guidance, the average bee will track it down in about four attempts. Smarter ones need fewer dances to get it right.

Do all bees behave in the same way?

No. Experts place bees in three different behavioural classes based on what they have learnt and their learning skills. Change agents are the “deliberative, decisive” workers that can make a major change to initially learned preferences. They are opportunistic and reactive. The ditherers are “fickle, circumspect” bees that can change their preferences only a little bit, while the no-gos are “stay” bees that refuse to show reversal learning and do not change from their initially learned preferences. They are stubborn and fail to be impressed by any change.

Drones

Role of the drones

• A drone’s lifting capacity comes into play during mid-air mating. This allows the drone, along with the much weaker queen to which it becomes attached, to stay airborne.
• Most drones never mate. Those that do mate, do so only once before dying of shock, having inflating their endophallus with almost all the haemolymphic fluid that their body contains.
• They carry about 16.1mg of honey with them to feed on when taking off for a mating flight.
• Drones are much bigger than worker bees.
• On average they fly 19.3km/h, compared to the 21.9km of forager bees. Their flight range is 6km, which is six times less than that of worker bees. Both classes have a top speed of 28km/h.

Bee-Ware

Bees are social insects, but some bees exhibit less than socially acceptable behaviour:

• Burglars. Plants produce sweet nectar to attract insects so that they can be pollinated. But some bees sidestep this process by “stealing” nectar from a hole they have cut at the base of the flower. 
• Highway robbers. A few incidences have been noted of bees stealing pollen from other forager bees.
• Raiders. When times are tough and food sources are low, colonies are known to attack one another during very organised raids to steal honey.
• Stealthy invaders: Parasitic workers sometimes take over entire colonies. This often happens with Cape honeybees who enter the colony of a different subspecies. By activating their ovaries to produce queen pheromones, they can turn into false queens. This can end in two ways: either through a lethal fight that the actual queen invariably wins, or with the false queen going into hiding somewhere in the colony.

Keeping up with cleanliness

Bees are very particular about keeping their hives and themselves clean, sanitised and free of honey.

Being covered in honey is like a death sentence, as the substance clogs their pores and they can suffocate. It makes flight difficult too.

Bees groom themselves whenever they can.  

Dedicated in-hive worker bees ensure nest hygiene and sanitation. They clean off any honey in the colony or on another bee.

Not a drop of honey is wasted. It is diluted, then taken up into the honey stomach of bees for consumption, to feed to others or to deposit into honey cells.

Bees produce sterile wax to seal filled cells. These caps prevent honey from spilling on bees. The wax contains fatty acids with antibiotic compounds.

In-hive worker bees constantly remove debris such as dead insects. Some polish empty comb cells until they are clean and shiny – ready for the queen to lay eggs.

Bees always defecate outside their nest. In winter, when their metabolism is low and they tend to stay in the hive, many take cleansing flights together.

Nests are lined with propolis or “bee glue”, which is composed of collected plant resin. Propolis contains many antiviral and antibiotic properties.

Small hive bees sometimes invade nests. African honeybees will simply move away and start anew elsewhere. If not, worker bees actively feed rather than fight beetles. They herd them into inaccessible cracks and corners of the nest where they are no bother.

Bee(ing) healthy

Colonies can suffer from infectious diseases, pests and parasites.  

A nest maintained at 35°C and 60% relative humidity is ideal for bacteria and fungi to spread.

Bees forage on almost sterile plant products. They encounter bacteria only when they gather contaminated water.

Most infections are transmitted during interaction with other honeybees – for instance, when one colony steals honey from another or when disorientated bees end up in the wrong colony.

Bees have very low natural immunity. Very few genes protect them from diseases. Fortunately, the plant products they feed on contain many disease-fighting compounds.

Nectar contains antimicrobial compounds. These benefits are carried over when honey and food jelly is produced. It prevents nectar from fermenting if contaminated by bacteria and fungi.  

Hives are lined with propolis or “bee glue”, which contains strong antiviral and antibiotic compounds that help treat infections.

Making a beeline for meals

Bee larvae are initially fed only food jelly, a protein-rich, sugary white liquid secreted from the glands of nurse bees.

Queen larvae feed on queen jelly exclusively as this speeds up their development.

Once a mixture of honey and pollen is added to a larva’s diet, it becomes a worker bee.

A male brood consumes a similar diet, but are fed longer and therefore grow bigger.

Foraging bees feed on some of the nectar and pollen that they collect. The rest they deposit in the hive to be turned into honey. In winter, sources of nectar and pollen are limited; worker bees then consume stored honey.

Mating behaviour

A queen bee’s sole purpose is to lay as many fertilised eggs as possible throughout her lifetime.

Bees have an extremely polyandrous society, as a queen will mate with as many drones from as many colonies as possible.

She mates only once in her life. For two to three days, she sets off around midday on 30 minute-long mating flights.

Mating takes place in mid-air, some distance from the colony and the safety of the hive.

A queen flies around and releases plumes of pheromones containing the so-called “queen substance” – 9-oxodecenoic acid (9-ODA) – at a designated spot, called a drone congregation area.

Drones pick up these chemicals with their highly selective, specialised antennae. They find even a mere hint of it irresistible and set about locating the queen by flying upwind towards her.

Drones start congregating as more and more detect the odour trail a queen leaves behind.

This provides a visual cue for other drones to join the group and attempt to follow the receptive female.

The queen can mate with as many as 70 drones during this outing.

A sample of semen from each of the males she mated with is stored in her spermatheca, which is part of her female reproductive tract.

Once her ovaries are activated, she never mates again.

Honeybees hold the world record for the lowest intracolonial relatedness between colony members. This is the result of the extreme polyandrous multiple mating of the queen, and the mixing of semen in her spermatheca. Whenever a worker meets another one in the hive, she will in most cases encounter a half-sister rather than a super-sister.

When the queen returns to her hive, drones from her own colony do not respond to her. This could be because they are used to the scent of her pheromones, or because she releases the scent only at drone congregation sites during flight.