Tag Archives: bees

How many native bees fit into six car parking spaces?

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Two-fifths of a tennis court. About six car park spaces. Three-tenths of an IMAX screen.

That’s the size of my front yard. Yet despite its limited expanse, and its densely urban situation 10 km north of Melbourne CBD, my yard is habitat for at least five species of native bees.

I began watching the bees closely last year in lockdown. The tiny, faintly metallic Sweat Bees (Homalictus) are most common. They appear first in Spring, visiting the Wahlenbergia, the Oxalis weed in the lawn, the strawberry, and rocket flowers; anywhere there’s pollen.

Later, the bold and stripey Lipotriches turn up. Like rock-climbers gripping an overhang, they lock themselves upside down to the anthers of dangling Dianella flowers, emitting short zip-like buzzes as they work with methodical focus.

Then when Summer days begin to blaze, the hyperactive Resin Bees (Megachile) arrive, with that distinctive ember thumb print on their behinds. They fire around the yard like deranged bullets, collecting pollen and scouting for cracks to nest in.

That such biodiversity endures in this landscape—once grassy woodland, now houses, roads, and light industrial—is a testament to these species’ resilience. But their persistence also begs the question of which species might now be absent, less tolerant of such drastic change.

The White-headed Digger Bee (Amegilla albiceps) is one such bee. Large, rotund, and covered in a pelt of golden and white fuzz, one has not been recorded in Melbourne for at least 70 years, perhaps longer. In a Summer free of travel restrictions, I’ll leave town to seek the White-headed Digger. But for now, I’ll keep discovering the delightful locals. It’s Homalictus season now.

This mini essay was originally written for the Urban Field Naturalist Project

The native bees of Moreland City

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Bees are an effective treatment for depression. Well, my depression. And specifically the kind of malaise that comes from being locked out of our national parks and wild places for a second Spring running.

After monitoring my small front yard last Spring-Summer, I knew there was a set of small but diverse native bees that revealed themselves when the weather was warm and the yard was blooming. This year, I’ve decided to go deep and get to know them a whole lot better.

Getting even a basic knowledge of the 2000 native bees of Australia is a very big task. Getting to know the native bees of a single 50 km2 local government area (where I live) is much easier. So I set out to reconcile all the official and unofficial records for native bees within Moreland City LGA (just north of Melbourne CBD), to build a species list. And after going to that effort, I figured the local community would probably also like to have that information. So here is version one of the ‘Native Bees of Moreland‘ infographic (PDF link):

Building the inventory of Moreland’s bees

I started by pulling all of the records for bees in Moreland LGA from Atlas of Living Australia. After taking out the two introduced species, there were 12 species-level identifications plus 52 records for bees identified only to genus or subgenus. I then validated the species identified against their geographic ranges to exclude any obviously erroneous records. After that I reviewed iNaturalist records for bees in Moreland to see if I could identify any species that did not appear in the Atlas records.

My summary from this process is in the table below:

SpeciesStatusNotes
Amegilla (Zonamegilla) assertaReliably presentA. chlorocyanea also possible given distribution, observations in nearby LGAs, and iNaturalist records
Lasioglossum (Homalictus) sp.Reliably presentNo species-level identifications confirmed. But the genus is very common. At least two species are in Moreland. Possibly L. punctatus, L. brisbanensis, L.urbanus, L. sphecodoides
Hylaeus (Prosopisteron) littleriReliably presentUnlikely to be the only Hylaeus species in the area
Hyleoides concinnaRare and presentNo record since 1946, however one record from neighbouring LGA, Mooney Valley, 2017
Lasioglossum (Chilalictus) calophyllaeReliably presentCommon and recent records
Lasioglossum (Parasphecodes) hiltacusHistoricalNo record in the LGA since 1956
Lasioglossum (Chilalictus) lanariumHistoricalNo record since specimen from 1894
Lipotriches (Austronomia)Reliably presentNo identified specimens, but iNaturalist observations confirm the genus is present
Megachile (Eutricharaea) obtusaHistoricalNo record since specimen from 1906
Megachile erythropygaReliably presentPinned specimen from 1987. iNaturalist observations since
Megachile (Rhodomegachile) deaniiDoubtful recordFar outside known distribution. Must be erroneous.
Braunsapis sp.Doubtful recordB. unicolor and B. plebeia specimens from 1958. Very far from known distribution. Must be erroneous records.

Clearly, for a very populous area, there are very few records. This is the case for not only bees, but insects in general. An added challenge is that it is often difficult to diagnose bees to species level. Together, that means it has been very easy to find bees that have never been recorded in the area.

For example, the most common small bee in my yard is a tiny, dark Homalictus with a faint green wash on the thorax. It most closely resembles Lasioglossum (Homalictus) sphecodoides, but this species has never been recorded in the area – presumably because no one with the right taxonomic expertise has collected bees, or examined Homalictus specimens from Moreland. Indeed, no species-level identification for a Homalictus has been made for Moreland at all.

  • Lasioglossum (Homalictus) sphecodoides? Collected from an Oxalis flower in my lawn

In the first-bee hunting trip I took outside my yard this Spring, I even recorded a new genus for the area. I caught both male and female reed bees – Brevineura sp., flitting around a flowering Diosma in the cemetary.

  • Brevineura sp. male – a genus not previously recorded in Moreland. Brevineura has recently been elevated to genus from its previous status as subgenus of Exoneura. Thanks to Mike Schwarz for the information.

Then there are those historical records – bee specimens collected 60 – 100 years ago and not seen since. How tantalising! Perhaps they are extinct in the area? Or maybe they are just so rare and scarcely recorded. Well not long after finalising the infographic, I rendered it instantly out of date by finding a Lasioglossum (Parasphecodes) hiltacus for the first time in Moreland since 1956.

  • Lasioglossum (Parasphecodes) hiltacus. Collected from Fawkner Cemetary. Thanks Ken Walker (Museums Victoria) for some help with identification.

In just two short trips outside the house I’ve recorded a new genus to the area and made the first local observation of a species since 1956. While I’m aware that our small, arbitrary local government boundaries bear no influence on ecology, it does make a useful context for illustrating just how under-studied is our urban bee biodiversity.

We don’t know what pollinates most Australian plants.

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Australian flowering plant diversity is legendary. Within an hour trip outside of our major metro centres anyone can quite easily witness unique Australian plant diversity in subtropical forest (Brisbane), grassland (Melbourne), and sandstone heath (Sydney). The diversity close to home is fairly well catalogued, and while it is hard to discover a new plant species, merely spending time around our native plants is very likely to reveal something that has never before been documented.

Something like 90% of our native plants rely on animals for pollination in order to set seed. Despite this, we simply do not know what pollinates most of our Australian native plants. The fact that the private lives for many of our native plants remains mysterious is due to their great diversity and the limited time and resources available to document what’s going on every day in the bush.

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Two native bees (Hylaeus (Rhodohylaeus) sp.) visiting flowers of the Broom Bush (Eremophila scoparia) in Western Australia.

And these uncharted interactions are totally critical for the functioning of our native ecosystems. Pollination underpins production of seed for the next generation, builds seed banks for post-fire regeneration, and also produces fruits and seeds that are critical food resources for our native animals.

Our ignorance of native pollination networks is therefore vastly out of step with their importance. This is illustrated in the example of bee declines, where we have all heard about the threats impinging on honeybees and pollination service for food crops, yet when it comes to Australian native bees, we lack the basic benchmark data needed to make a solid judgment about whether they too are declining*. It is therefore imperative that we commit effort to recording native pollination networks now, before they are lost to us. While it is hard for long term ecological monitoring projects to attract funding, ongoing development of automated imaging of flower visitors and large scale citizen science projects offer some promise for increased capability in filling this ecological blind spot.

But our ignorance here can also be thrilling. This means that every time you are in the bush, and witness an insect or bird taking nectar or pollen from a flower, there is a reasonable chance it has never been documented before. In my work with University of Melbourne I have been studying several native shrubs to understand their pollination, and for many of these species, it is gratifying to know that my work will be the first documented evidence of what is visiting them. But you don’t have to be a trained scientist to do this, you just need some patience, luck, and some fine weather. And while discovering and photographing an unusual native bee pollinating one of our native flowers won’t win you a Nobel Prize, I guarantee it will provide any enquiring mind with a hit of electric discovery every single time.

 

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Photographed on Mount Buffalo, Ken Walker (Victoria Museum) later identified this bee as the very rare Lasioglossum (Callalictus) callomelittinum. Few photos of it exist. This individual is buzz-pollinating a Fringe Lily (Thysanotus tuberosus).

 

Links for pollinator observations:

Bowerbird: Nature observations database

Wild Pollinator Count

Government pollinators repository

*But given native bees need native habitat, and native habitat is being cleared at astonishing levels, we can, with a high degree of confidence, say that native bees are declining too.