Could native bees be driven to extinction while scientists’ eyes are elsewhere?

It’s what scientists don’t know about native Australian bees that has them deeply concerned.

While there is no shortage of eyes on European honey bees — and the impacts varroa mite, pesticides, climate change and other threats have on their populations — there is a paucity of research on native bees.

That worries Australian scientists, including Kit Prendergast and Anna Carrucan, who say native bee species may be driven to extinction while no one is looking.

“The knowledge gap with native bees is a danger — there is so much we don’t know,” said Dr Prendergast, from the University of Southern Queensland.

“With honey bees we’re talking about one species. We know how to keep them, we know … how to improve their nutrition, their diseases and how they nest.

“There are thousands of native bee species and in some cases, we don’t know their distribution, we don’t know what they forage on, where they nest or their population changes.”

Dr Prendergast said that “some have gone extinct and we don’t know”.

“There are lots of records of dozens of species collected 50 or 100 years ago and there is no further records of them,” he said.

Climate change a concern

There are more than 1,600 described bee species in Australia, and potentially several hundred varieties that are known but are yet to be scientifically described.

Dr Carrucan, a Victorian botanist and beekeeper, said while there was an absence of research on Australian native bees, it was not unreasonable to suggest some threats to honey bees may also be a problem for native species.

“Climate change is one [example],” Dr Carrucan said.

“Increasingly hotter and drier weather systems will affect how well trees flower and therefore how much pollen and nectar they provide for insect foragers or even if certain plant varieties and landscapes persist.

“It would be a similar scenario with losses due to pesticides on crops, as would it be with changes to the environment, such clearing the landscape for expanding urban sprawl.”

The green carpenter bee (Xylocopa aerata) on Kangaroo Island was almost entirely wiped out by the bushfires in 2019-20. There had formerly been a population in the Grampians in Victoria, but that population is now gone.

“There are still some in the hinterland around Sydney but the last known ones in Victoria were in the Grampians and now they are gone. That’s a tragedy, really,” Dr Carrucan said.

While few native bees produce honey — and practically none in commercial quantities — their value to Australian agriculture is considerable.

“They are a hidden, unpaid workforce that contribute as much as honey bees do to pollinate our food crops. It’s more than $14 billion per year of free work in measurable value for food and fibre,” Dr Carrucan said.

Identity crisis

While the European honey bee (Apis mellifera) with its familiar furry body and gold and black-striped pattern is easily identified as a bee, native bees come in a variety of shapes, sizes and colours.

Some can easily be mistaken for flies, while others resemble wasps, while some are missing the trademark stinger.

“Bees have two pairs of wings whereas flies only have one pair,” Dr Carrucan explained.

“Wasps and bees are closely related.

“It’s believed bees evolved from wasps and are the vegetarian cousins to the omnivorous wasps.”

Even the common names given to some native bees confuses rather than helps identification, which was why scientists preferred to use scientific names.

“Communicating accurately about biodiversity is absolutely fundamental if we’re going to conserve species, and if we’re going to raise awareness,” Dr Prendergast said.

“A common name doesn’t map onto taxonomy. It can refer to one species, it can refer to a genus, it can refer to a family and you have no idea which.”

Dr Prendergast said common bee names could be misleading. 

“A really common bee name is blue banded bee, [but] there are many bees with blue bands,” she said.

“Quite a few of them are Amegilla, which is a genus, but there’s also bees with blue bands from the Nomia group, which is from an entirely different family.

“Even within the Amegilla blue-banded bee genus, some have blue bands, some have white bands, some have green bands, and some have no bands.”

Common names can also vary by country or location.

A species may be called different things in two different countries, states or locations, and it will often be called different things in different languages.

“The beautiful thing about scientific names is that they’re all in Latin and are the same no matter where you are in the world,” Dr Prendergast said.

So how do Australia’s native bees differ from introduced species?

Native bees

Stingless honey bees

There are three main genera of Australian stingless honey bees — Melipona, Tetragonula and Austroplebeia —  which produce very small quantities of honey.

Meliponini, sometimes called sugarbag bees or bush bees, are about a third the size of European honey bees.

A fourth genera of stingless honey bees — Scaptotrigona — is primarily found in Brazil

Euryglossinae bees 

The Euryglossinae genus (family Colletidae) includes some of the smallest bees, some of which look not unlike flies or wasps.

These bees are endemic to Australia and are very specialised to native flora — a suburban garden with exotic flowers would be like a desert wasteland to them.

Resin bees and leaf cutter bees

The Megachile genus of solitary bees includes native Australian species that use plant resin to construct their nests.

Australian leaf cutter bees typically belong to a Megachile sub-genus called Eutricharaea. The females have cutting mandibles for carving discs out of leaves to line their nests with.

Carpenter bees

Carpenter bees are generally quite large, and belong the genus Xylocopa. The insects are called carpenter bees because they make their nests by chewing wood.

Cuckoo bees 

This is a diverse group of bees from unrelated genera, which have independently evolved to parasitise other bees by laying their eggs in the nests of other bees. Once hatched, their larva often consumes the host species’ larvae.

Blue banded bees 

This term usually refers to bees from the Amegilla genus, but not all of them have blue bands. There are so-called blue banded bees where the bands are cream, white, pale blue and vivid blue.

Teddy bear bees 

This is another group within the Amegilla genus , which is typically brownish in colour and similar in size to a honey bee but furrier and stockier.

Exotic bees

Bumblebees 

A diverse group of large, hairy bees. Just one species is found in Australia, Bombus terrestris, which was introduced into Tasmania.

European honey bees 

When people think bees, Apis mellifera is what most people imagine. These insects are highly social compared with other bees and are farmed for their ability to produce high quantities of honey.