The native bees of Moreland City

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.

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.

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.

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.

Photos from the field: The Great Western Woodlands.

The Great Western Woodlands (GWW) form the largest tracts of temperate woodlands left on Earth. They hold approximately 30% of Australia’s Eucalypt species, and close to 20% of Australia’s plant species overall. This is truly an overlooked gem of Australian biodiversity. Last Spring I was lucky enough to visit for my work on pollination in our native plants.

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My target there was Eremophila, a genus of approximately 250 species largely confined to arid and semi-arid Australia. The GWW represents one of the centres of diversity for the genus, and so I chose it as a likely spot to set up a new study contrasting bird and insect pollination.

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Eremophila alternifolia was one of about 15 Eremophilas I saw flowering despite the drier than average conditions.

I was joined by perhaps the best kind of field assistant: a trained and accomplished professional ecologist who also happens to be my beautiful wife. After driving 2800km from Melbourne to field sites near Norseman, Western Australia, we spent a little under two weeks observing pollinators, surveying and mapping populations of plants, and collecting samples for population genetics.

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One of the many viewpoints south of the Nullarbor Plain.

I left in awe of the scale of these woodlands, in love with the peace and isolation they offer, and a bit concerned over their insecure future. Fully 60% of the GWW is tenured “unallocated Crown land”, unmanaged and open access. With more visitors, and more appreciation of the value of these vast woodlands, I hope we can find a way to secure more of it into ongoing reserve for future generations.

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The bluebush understory contrasts dramatically with red sand in many areas. Front left is one of my study species Eremophila scoparia.

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The whole region is dotted with salt-pans.

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As predicted from the small, violet flowers, Eremophila scoparia was visited by a host of native bees.

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Eremophila decipiens has characteristic bird-adapted flowers.

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Camera traps being expertly arranged by Samantha. Footage revealed that E. decipiens was being visited by a range of honeyeater species.

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Eremophila calorhabdos

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This spectacular Grevillea hid a massive bloom of flowers underneath it

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The inflorescences are held on stems that grow along the ground underneath the shrub. The very long style with pollen-presenter is suggestive of adaptation to birds, but mammals might not be out of the question.

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Eucalyptus loxophleba with daggy botanist for scale

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Majestic Salmon gum (Eucalyptus salmonophloia) with Samantha for scale.

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The serenity of wandering amongst giant Salmon gums at dusk was magic.

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Gleaming bark on Eucalyptus salubris

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Elevating on Lake Cowan. Photo: S. Vertucci.

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For the second half of the trip I was joined by collaborator and all-round legend Dr. Renee Catullo. I made us walk 10km to collect camp gear following a single poor decision.

Stay tuned as research results emerge. The study should tell us about the way pollen moves under bee and bird pollination, and how those fine scale patterns play out on a grand landscape level.

Unearthing diversity in fungal dark matter

To be born an orchid is a most unlikely thing. First your parents must be pollinated, which is difficult. Orchids are both rare, and rarely pollinated due to the bizarre and dishonest means by which they go about attracting pollinators. Added to that, orchids often rely on a single species of pollinator to do the job.

Let’s say, however, that your orchid parents do manage to achieve fertilization. Your orchid mother will produce many thousands of tiny dust-like seed, which will be jettisoned into the wind. Unlike most seeds, you have no maternal energy investment to power your germination and first days as a seedling. Instead, you must rely on blind luck to land you within reaching distance of a strand of soil fungus. This fungus is the wet nurse to bring you into the world, invading the seed coat and hooking the young orchid up to a network of fungal strands that pervade the soil. Tapping into this network provides you with the first sips of carbohydrate and nutrient you need in order to build your first green leaf and begin to stand on your own roots. But it is not enough to land near any fungus. Many orchid species require fungal partnership with a specific species of fungus for this to occur at all. Multiplied together, it is a wonder that orchids ever overcome these odds to propagate themselves into the next generation.

The southwest of Western Australia is rightly famous as a global biodiversity hotspot. The area is particularly rich in orchids, and the spider orchids (Caladenia) are some of the most impressive and diverse of the region’s main orchid groups. In 1967, University of Adelaide researcher John Warcup discovered in association with Caladenia a new genus of fungi. Today those fungi are called Serendipita, and although we have known of them for around 60 years, there have been less than a handful of species discovered and described.

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The spider orchid Caladenia arenicola was one of those sampled in the study

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White spider orchid (Caladenia splendens)

Ubiquitous yet invisible

Although related to mushrooms, Serendipita fungi have not been observed producing the conspicuous spore-bearing fruit bodies we usually use to find and identify them. This makes them largely invisible, and I have therefore never observed them in the wild. Despite that, recent research using DNA sequencing has found them to be absolutely everywhere. Inside all kinds of plants, outside all kinds of plants, and distributed from the equator to Antarctica. It is clear then that there must be a hidden biodiversity of these species siting, waiting to be discovered.

My study took a wide sample of southwest WA spider orchid samples and assayed them for the presence of Serendipita fungi. We then sequenced the DNA of all the fungi we found, and used a new analytical technique for dividing that DNA sequence diversity into units that are probably species. This is currently the only way to sensibly identify Serendipita fungi, as they all look completely alike and do not produce spores in the lab.

We found a total of eight species of Serendipita fungi, including the original species discovered by Warcup back in the 60s. These came from a total of 18 species of orchid. At some sites where we sampled multiple orchid species, we found six species of Serendipita, meaning that the fungi were as diverse as the orchids!

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Lying just below the soil horizon, that swollen, yellow stem bit is called the “collar”, and its where all spider orchids keep their fungus.

Untapped agricultural potential?

Although we have chosen to study these Serendipita in association with orchids, their wide host association has got other researchers interested in their role in plant health and application to agriculture. For example, Warcup’s species and one other have been used in experiments (and patent applications) showing inoculation with Serendipita results in profound benefits for the host plant, including:

  • Increased plant weight in maize, poplar, parsley, tobacco, barley, wheat, switchgrass and Arabidopsis
  • Enhanced grain yield in barley
  • Accelerated plant development in barley
  • Greater seed set, increased growth and faster flowering time in tobacco
  • Increased wheat yield in poor soils
  • Improved nutrient uptake in chickpea and lentil
  • Improved salinity tolerance in barley
  • Enhanced protection against root and stem pathogens in barley
  • Improved resistance to stem pathogens in tomato
  • Stronger defense response against mildew leaf pathogen in barley
  • Increased essential oil content in fennel and thyme

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Figure 7 from Ray and Craven (2016): Root growth in winter wheat in Serendipita vermifera inoculated plants (left) versus control (right)

These proven benefits make Serendipita a potentially powerful tool to enhance plant productivity and stress tolerance in crops. Furthermore, application of Serendipita fungi could be an organic alternative permitting growers to lower the application of unsustainable and ecologically harmful synthetic fertilizers. Our knowledge of plant-Serendipita associations in the wild suggests that these relationships are more prevalent in nutrient poor soils such as those in southwest WA. They are probably one factor that allows our plant diversity to thrive in such weathered, poor soils. This means that species of fungi that have evolved with the nutrient poor soils (like those discovered in this paper) might be untapped tools to enhance agriculture taking place in those very same soils.

 

(Erratum: This story was edited to replace the figure attributed to Ray and Craven (2016). The first image I used was one showing Arabidopsis capability for mycorrhizal association. Arabidopsis is typically thought to be a non-mycorrhizal plant, which is why this is interesting. The image however showed slower growth in the mycorrhizal treatment. A related Serendipita has been shown to enhance root growth in Arabidopsis however. I have now updated the post with a more appropriate image of root growth gains in wheat. Thanks to Pawel Waryszak (@PWaryszak) for pointing this out.)

 

My study:

Whitehead, M. R., Catullo, R. A., Ruibal, M., Dixon, K. W., Peakall, R., & Linde, C. C. (2017). Evaluating multilocus Bayesian species delimitation for discovery of cryptic mycorrhizal diversity. Fungal Ecology, 26, 74-84.

Further reading:

Weiß, M., Sýkorová, Z., Garnica, S., Riess, K., Martos, F., Krause, C., … & Redecker, D. (2011). Sebacinales everywhere: previously overlooked ubiquitous fungal endophytes. Plos one, 6(2), e16793.

Weiß, M., Waller, F., Zuccaro, A., & Selosse, M. A. (2016). Sebacinales–one thousand and one interactions with land plants. New Phytologist, 211(1), 20-40.

Ray, P., & Craven, K. D. (2016). Sebacinavermifera: a unique root symbiont with vast agronomic potential. World Journal of Microbiology and Biotechnology, 32(1), 16.

Bokati, D., & Craven, K. D. (2016). The cryptic Sebacinales: An obscure but ubiquitous group of root symbionts comes to light. Fungal Ecology, 22, 115-119.