About Sugarbag Bees

There are over 20,000 species of bees around the world. The most well-known species is, of course, the European honeybee. Honeybees were imported into Australia in 1822, although there were already over 2,000 species of native bees living here in Australia. Only 11 of these Australian native bee species produce honey, all of them stingless and belonging to either the Tetragonula or Austroplebeia genera. They are also called "stingless bees" and "sugarbag bees".

None of the species of honey-producing native bees have common names, but are generally called by their scientific names. Out of the 8 stingless bee varieties present in Queensland, we believe we have 3 varieties here where we live in Central Queensland: tetragonula hockingsi, austroplebeia australis, and austroplebeia cassiae.

Australian native stingless "sugarbag" bees on a rose. These bees may be considered "stingless", but they sure can bite!!

I am not a scientist or expert of any kind, so this is an article using my own observations and another person's in-depth studies of native bees and sugarbag rather than my own expertise or knowledge in the area. My main reference for information about these sugarbag bees is "The Australian Native Bee Book" by Tim Heard, an entomologist and expert about Australian native bees. I highly recommend this book if you are interested in learning more about sugarbag bees!

A Bee's Lifecycle

Just like honeybees, sugarbag bees are social bees that build a colony which includes one queen bee, hundreds of drone bees, and thousands of worker bees. Despite their much smaller size, sugarbag bees take longer to develop from egg to adult bee than honeybees, and they also live longer than honeybees.

A European honeybee with a sugarbag bee. Sugarbag bees can often be mistaken for flies. Photo credit: Tobias Smith, University of Queensland.

With honeybees, the queen bee lays a fertilized egg in a cell that the worker bees have built. After the egg hatches, the worker bees feed the larva until it develops into a pupa, at which point they cap the cell. Twenty-one days after the egg was laid by the queen, an adult worker bee emerges from the cell, ready for her 50-day lifespan of hard work, doing "indoor" work to begin with (cleaning and polishing cells, feeding and caring for the brood, tending to the queen, and building and repairing the honeycomb) and progressing to working out of the hive: guarding the hive entrance and foraging for nectar, pollen, and water. Cells are reused indefinitely for following generations of bees or until they need to be repaired or replaced.

However, with sugarbag bees, the worker bees partially fill each newly-built brood cell with enough food for the whole developmental stage of the new bee before the queen lays the egg in the cell. The workers then cap the cell and leave the young bee to hatch, feed, pupate and emerge all on its own. Fifty to fifty-five days after the egg was laid by the queen, an adult worker bee emerges very pale (newly-hatched pale adult bees are called callows), and darkens to her normal adult colour over the next few days. Over her approx.-100-day lifespan, she does lots of work that starts in the hive doing menial tasks like rubbish disposal, building structures and cells, and being a "nurse bee", and ends her days guarding the door and foraging for nectar, pollen and resin. Cells are not reused for future generations of bees; rather they are demolished and a new one is built for each bee, working progressively across the hive in such a way that it makes what's known as an "advancing front" (the newest cells) and a "retreating edge" (the oldest cells, almost ready for demolition).

Brood cells. Here you can see the advancing front to the left and the retreating edge to the right, with a gap in the middle.

With both honeybees and sugarbag bees, drones (males) hatch from unfertilized eggs and are about the same size as the worker bees, with their sole purpose in life being to mate with the queen. Honeybee drones hatch in 24 days, whereas sugarbag drones hatch in the same length of time as the worker bees, 50-55 days. They usually leave or are evicted from the nest before dying, so it is hard to determine their lifespan.

Honeybee queens are raised only if the hive is anticipating a need to swarm, if the colony becomes queenless, or if the elderly queen is failing. Queen bees develop from a fertilized egg the same as the worker bees. What determines that she will be a queen is that she is fed "royal jelly" as a larva, a food that is different from what any other bee is fed, and she is raised in a larger, specially constructed cell. There are usually multiple queens being reared at the same time, and it is the strongest, fittest bee who wins the "race" to become queen after hatching at 16 days. She kills all the rival queens before going out to mate with drones, which she does multiple times throughout her life of about 2 to 3 years. She spends her whole life laying eggs and being attended by worker bees.

In contrast, there are a continual reserve of virgin queen bees being raised in sugarbag bee colonies. A queen larva is fed the same food as worker bees, just in larger quantities, and she takes a few days longer to develop than worker bees and drones. In the case of a queenless hive or a failing elderly queen (sugarbag bees do not "swarm"), the workers select a virgin queen and allow only her to mate with the drones. This she only does once in her entire life of up to 4 years. Sugarbag queen bees are not attended by worker bees quite the same as honeybee queens, but instead tend to feed themselves.

Hive Structure

Honeybees build honeycomb, very precise in size and hexagonal in shape. They use some cells for brood (laying eggs and raising baby bees), some for storage of pollen, and some for making and storing honey. They chiefly use wax to build their structures, and tend to produce up to 45kg of honey per hive per year.

The shape and structure of sugarbag bee hives depends on the species of the bees. Generally sugarbag bees build small individual cells for their brood (with an advancing front and retreating edge, as aforementioned), which are not arranged in neat rows and columns like honeybee honeycomb but rather in a more "messy" fashion. There is an exception with the tetragonula carbonaria, a species found in SE Queensland and along the NSW coast, which build their brood in a spiral, as pictured.

Brood structure. (a) (b) and (c) are tetragonula carbonaria, the species from further south; (d) is tetragonula hockingsi, one of the three species we have here in Central Queensland. Photo courtesy of https://phys.org/news/2020-07-stingless-bees-tall-spiral.html, images courtesy of (a) Elke Haege; (b–d) Tim Heard.

The sugarbag bees then build their storage for honey and pollen as large "honeypots". They build intricate structuring for support, and either an inside or outside hive entrance, depending on the species. The tetragonula hockingsi builds with a majority of propolis, a mixture of resin and wax (which is very dark, as you can see), whereas the austroplebeia australis builds with a larger ratio of wax, which makes their hives lighter in colour. A hive of tetragonula hockingsi, the species that builds the largest hives of all the Australian native bees, produces a maximum of up to 1kg of honey per year, which explains why it is very hard to find on the market - and also explains the price of it when you do find it to buy!

A hive in a log - I think this is tetragonula hockingsi. You can see the advancing front and retreating edge with the gap in the middle to the right, as pictured earlier. To the left there are pollen and honey storage "pots". The sheets that you can see obscuring most of the hive is called an "involucrum", a soft layer of propolis built as a protective layer around the brood chamber. The thicker-looking, darker sheets are "batumen", made of propolis and debris, very hard, and used as protection between the hive and the rest of the cavity in the log, which may be home to termites, ants, millipedes and other creepy crawlies. Woe to the beetle or millipede that dares to enter the hive - the bees will coat and entomb him in resin!

Lots of pollen and honey storage pots in this log!

This blog post will get tediously long if I keep writing, so look out for more posts about sugarbag bees over the coming weeks! Next time we will be learning more about their honey.