Burrowing bees

Spring has run its course in the mid-west of Western Australia.  Flowers have bloomed and bees have played their role as pollinators.

While driving along a sandy track at Eurardy Reserve, we spotted a colony of native burrowing bees. They belong to a genus of solitary, short-tongued bees: Dasyhesma.

Female bees hover above the burrow entrances to find their own, then drop down and dig as shown in the video below.

At the bottom of the burrow, they build a series of brood cells, which they stock with nectar and pollen and deposit their eggs. The larvae eat, grow and develop into young adults which dig their way to the surface to begin a new cycle the following spring.

At Charles Darwin Reserve, volunteers Geoff and Wendy Corrick spotted a different type of burrowing bee. This one is a relative of the blue-banded bee and belongs to the genus Amegilla. It is most likely Amegilla paracalva.

These bees are also solitary – each with their own burrow. When building a new burrow, a female selects a site and begins to excavate by biting at the soil with her mandibles. The soil is periodically wet and softened with liquid from the mouth.

This species often build turrets around the entrance to their burrow.  They were very wary of me – you can see in this second video that they had to build up the courage to leave the burrow with me watching so closely!

Australian native bee facts:

There are an estimated 2000 species of native bees in Australia. Some different types include carpenters, leaf cutters, lodgers, cuckoos, short tongued and long-tongued bees.

• Sugarbag bees found in the tropical north are the only highly social bees in Western Australia – most other species are solitary (i.e. they do not build hives).
• Females build their burrows without the aid of workers. The sole function of male is to locate and fertilise females so they spend their time patrolling flowers and burrow entrances.
• Most native bees burrow in the ground, or otherwise in dead or rotting wood. Other species use existing holes in dead wood, hollow stems or old wasp nests.
• Many native plant species have evolved close relationships with native bees and some are pollinated by only one native bee species. These specialist bees often show anatomical adaptations to their preferred plants.

Thanks to Terry Houston of the WA Museum for his help with identifying and providing more information about these amazing critters.