Meadow in a box

Our guest blogger today is Simon Whitworth, currently working as a Countryside Officer at Aberdeen City Council. His enthusiastic work to help pollinators has really caught the eye, and below is his story about the catchily named ‘Meadow in a box’.

Last autumn an idea grew in my head, planted there by some projects going on around me in Aberdeen City Council’s Environmental Services: Aberdeen B-lines, a change in grass cutting to encourage wildflowers, and an increased interest from schools in wildflowers and pollinators.

As Acting Countryside Officer, up from the ranks of the Aberdeen’s Countryside Rangers, I have increased powers of purchasing, and closer lines of communication with council higher-ups. I still don’t really know what a Performance and Development Manager does, or a Technical Officer, but I do know they’re useful people to ask about projects and how to generally ‘Get Things Done’.

Using my enhanced powers I thought I’d transform my box-based idea into an actual living thing, and that it should have a name. What better than something very literal (and I apologise to anyone who thought of this name first!)? So Meadow-in-a-Box was born, only without boxes or anything to make it a meadow.

Having decided that shop-bought planters were too expensive I decided to explore the world of the Scottish Prison Service, and secured an order for one hundred planters built by inmates of HMP Grampian, Peterhead, in their joinery workshop.

While more planters were in production, the first ten were collected and filled with compost by the gardening staff of Aberdeen City Council. The phrase ‘sturdy and rustic’ was used to describe the planters, and I like that description as it seemed appropriate to a wildflower meadow.

Filled with enthusiasm I set out to deliver the first ten Meadow-in-a-Box planters to Aberdeen City school early years settings. At the project’s genesis I’d emailed every head teacher in council-run schools, explaining my idea including its benefits for biodiversity, pollinators and the education of children in school nurseries. Evidently my pitch was put well, as more than thirty schools signed up their early years staff and pupils for a Meadow-in-a-Box.

So in May I delivered planters to ten schools and, at a few, had the pleasure of working with the children as they enthusiastically sowed wildflower seeds provided for free by Sarah Smyth of NatureScot.

The seed mix includes black knapweed, red clover, devil’s-bit scabious, ox-eye daisy, red clover, selfheal and yarrow, so provides a beautiful palette of red, white and purple. As I’m sure you know, each of these wildflower species is native to Scotland and great source of nectar for pollinators such as bumblebees, moths, hoverflies and butterflies.

As October unfolds into Autumnal weather, the Meadows-in-a-Box have seen full flowering as they painting playgrounds of ten schools with colour. The plants will be dying back now, marshalling their resources for growing next year.

In 2024 the first ten Meadows-in-a-Box will be joined by another thirty, located at more schools and also care homes and sheltered housing. Aberdeen will see a bit more colour among the grey granite buildings, contributing to the nectar value of the city and helping pollinators thrive between the streets and houses.

I have plans to grow Meadow-in-a-Box beyond Aberdeen so who knows: perhaps you’ll soon see a Meadow-in-a-Box near your house or workplace, with its attendant kaleidoscope of butterflies and bumblebees drifting amidst the wildflowers?

Reluctant givers and industrious takers

By Athayde Tonhasca

For bees, pollen is an indispensable source of protein for egg production and larval development. So if they had it their way, bees would scoop up every pollen grain from a flower. And they are good at it, taking 95 to 99% of the powdery stuff back to their nests. The ‘wasted’ 1 to 5% of pollen that bees accidentally drop off or is left clinging to the bees’ hairs, is all a plant has for pollination.

Bees such as honey bees (Apis spp.) and bumble bees (Bombus spp.) carry almost all the pollen they gather in their corbiculae, or pollen baskets. From the Latin diminutive of corbis (basket), the corbicula is a shallow leg cavity surrounded by a fringe of elongated setae (‘hairs’). These bees, unsurprisingly called corbiculate bees, moisten the pollen with regurgitated nectar and saliva, so that it can be bundled up nicely for transport and easily unloaded once bees are back at their nests. 

A European honey bee’s pollen basket © Gilles San Martin, Wikimedia Commons.

A corbiculate bee grooms herself regularly to remove stray pollen grains stuck to her body: most of them will be scooped up and stored securely © Ragesoss, Wikimedia Commons.

Other bees carry pollen attached to their scopa (Latin for ‘broom’), which is an area of dense, stiff hairs on the hind legs (typically in the families Halictidae and Andrenidae) or on the underside of the abdomen (mostly in the family Megachilidae). These non-corbiculate bees are not as tidy as their corbiculate counterparts: they do not wet and compress the pollen, but instead take it away just like dust particles clinging to the bristles of a brush or a broom.

The scopa of a megachilid or leaf-cutter bee © Pollinator, Wikimedia Commons.

Transporting pollen on the corbiculae or scopa makes a world of difference for pollination. Pollen tightly packed in the corbiculae is not easily stripped off by floral structures when the bee visits another plant, and it quickly loses its reproductive viability because it has been wet. Pollen on a scopa is kept dry and loosely attached to the bee, so it has a greater probability of being dislodged and resulting in plant fertilisation. 

A load of pollen in a bumble bee’s pollen basket © Tony Wills, Wikimedia Commons, and a chocolate mining bee (Andrena scotica) with pollen loosely attached to its legs.

Regardless of how pollen is hauled away, bees’ efficiency puts plants in a jam. They need flower visitors for sexual reproduction, but the greedy blighters want it all for themselves. Pollen is metabolically expensive, so a plant can’t afford to produce lots of it and then lose most to palynivores (pollen eaters). But if it produces too little, bees may not be interested in dropping by.

To deal with this dilemma, plants have evolved strategies to keep visitors coming and at the same time not making it easy for them, thus minimising pollen profligacy. One cunning way to do this is to interfere with bees’ ability to groom themselves, so that more pollen grains are likely to be missed and end up on a receptive flower. To do this, there’s nothing better than nototribic flowers, which are built with an elaborate lever mechanism that makes stamens and style touch the dorsal surface of a visiting insect. This device is common in sage, mint and rosemary plants (family Lamiaceae), and in figworts (family Scrophulariaceae).

When a male Anthophora dufourii probes a Salvia hierosolymitana flower for nectar, its stamens are lowered to deposit pollen on the bee’s back © Gideon Pisanty, Wikimedia Commons.

Bees use their front legs to wipe their heads and antenna, and their middle and hind legs to clean their thoraxes and abdomens – you may have watched a bee or other insect doing these cleaning manoeuvres. But the space between their wings is a blind spot: think about an itch right between your shoulder blades, and you will understand the bee’s pickle. The pollen grains deposited on this hard-to-reach area are likely to escape grooming efforts and be taken to another flower.  

Pollen of meadow clary (Salvia pratensis) seen under UV light on the back of B. terrestris © Koch et al., 2017.

Some flowers hide pollen at the bottom of their corollas, and visitors such as the fork-tailed flower bee (Anthophora furcata) must creep into these narrow, tubular structures that don’t allow much moving about. The bee vibrates her flight muscles to release the pollen, which gets attached to her head. She pulls out of the flower and scoops up the pollen with her front legs, but not all of it. Some grains become stuck to the thick, curved hairs sticking out between her antennae; these grains could end up on another flower. 

A fork-tailed flower bee has to use her head – literally – to pollinate © Dick Belgers, Wikimedia Commons.

The common hollyhock (Alcea rosea) and other mallows (family Malvaceae) use a different tactic: they induce some bees to be less efficient gatherers thanks to their echinate pollen. Besides being prickly (echinate: covered with spines or bristles), these pollen grains are relatively large, thus difficult to handle and to mould into neat pellets. These features constitute a headache for corbiculate bees, the proficient packers, but are less of a problem for sloppy pollen harvesters such as solitary bees. As a result, more pollen grains are likely to be dislodged from bees who bother visiting these plants, increasing their chances of pollination. 

Echinate pollen grains from Malvaceae and other species © Konzmann et al. 2019.

Plants have developed other adaptations to minimise pollen harvesting, such as complex flower structures or progressive pollen release to force pollinators to make repeated visits. Some species hide pollen inside poricidal anthers, others produce indigestible or even toxic pollen so that only a few specialised pollinators can get to it; the palynivore hoi polloi is kept at bay. Many plants such as orchids are downright cheats: they lure pollinators with scent or visual mimicry but do not give away any nectar or pollen in return. 

All these adaptations demonstrate that pollination is a negotiation between parties with conflicting interests. There is nothing altruistic here, bees and flowers are taking advantage of each other in an evolutionary give and take. Granted, this mutual exploitation has been fine-tuned in order to avoid disastrous imbalances. Plants can’t afford giving away too much pollen but can’t risk being too stingy; bees would take all the pollen they could handle, but settle for what’s available as long it’s worth their time and energy. Overly parsimonious plants and overly rapacious bees would collapse the relationship. Every plant-pollinator combination is an example of a mutually beneficial compromise; it’s natural selection as its best.

Farewell summer, hello autumn

We have reached that time of year when we drift gently into autumn.  Summer fades away, and many popular pollinator resources come to an end.  Verbena, a garden star, is one I will be particularly sad to say goodbye to.

Verbena (c) Wikipedia Commons

Gardens can be incredibly important for our pollinators. It is reckoned that gardens occupy an area several times larger than that occupied by all of our Nature Reserves. And because gardens are different the length and breadth of the country they bring enormous variety, which is good as different pollinators have different preferences and needs. Add the fact that together gardens can form effective wildlife corridors and you can see why we place such environmental value on them.

Verbena, known to some as vervain, is a great pollinator plant. It’s nectar rich, and it isn’t just bees that appreciate it. Moths, butterflies, wasps, and hoverflies will also visit. 

As ever there is a medicinal story behind this plant – in this instance one of the more notable uses was as a counter to high blood pressure.

In Madrid we can uncover a more unusual use for verbena’s lilac flowers. The blooms were traditionally worn as dazzling lapel ornaments during a trio of Madrid festivals. The plant also caught the eye of famous American author William Faulkner who included references to it in the final chapter of his 1938 novel The Unvanquished. Much earlier the artist Philippe Mercier captured verbena in one of his paintings which currently hangs in Dumfries Art Gallery.

At the start of 2023 the Romanian Postal Service issued a set of stamps which were ostensibly promoting “Green Pharmacy”. Included in the set of ten stamps was one highlighting verbena which the authors said had beneficial properties for preserving health and treating certain ailments due to – amongst other things – anaesthetic and anti-inflammatory qualities.

If you were designing a garden for wildlife, you would likely be tempted to include verbena. Not only is it tall, it has strong, narrow stems with few leaves which mean that you can easily see what is planted beneath it. This makes it a good ‘structural’ plant for those who like to design their garden a little. There is an agreeable amount of space around the flower heads all the better to appreciate the white, purple or lilac blooms and the pollinators which eagerly visit.  It certainly gives height to a garden, and goes well both in timing and shape alongside other umbels such as yarrow and wild carrot, as well as nasturtiums. 

Verbena comes in many varieties, both Slender and Garden Verbena are probably best viewed as annuals, whereas the purple flowering Verbena bonariensis (a name derived from Buenos Aires where it was apparently discovered) is more likely to survive as a perennial, but I suspect that in Scotland you may still need to molly-coddle it a wee bit.

Cosmos, another popular garden flower that bees are drawn to

There are other lilac/blue/purple plants I will be sad to wave goodbye for 2023 to – viper’s bugloss, borage, devil’s bit scabious. But I know we will see them again next year and I am optimistic that gardens in particular are increasingly bee-friendly.

We are getting there. More and more gardeners are planning flowering activity which fills the entire year, yet more are ditching any form of pesticides, even double blooms are seemingly dropping in popularity.  The wildlife gardening message, thanks to the sterling work of groups like Bumblebee Conservation Trust and Gardens for Life, is making a difference.

Here’s to autumn, and the in due course 2024 when we can meet up with verbena again.  

Tallinn’s pollinator corridor

Tallinn, Estonia’s vibrant capital, is steeped in history. Much of it has been turbulent, but historians might well come to reflect on a more gentle piece of recent history – the creation of The Tallinn Pollinator Highway.  What’s not to like about increasing species-rich meadows and floral strips that create a lively green corridor as good for people as it is pollinators?

The Pollinator Highway – Putukaväil – is a green corridor which sits in the northern districts of Tallinn. It largely follows a former power line route, and old railway embankments, in what is essentially a 13km urban linear park. It’s now an award winner having scooped the EU Green Capital Winner 2023.

Cutting a green swathe through several districts the route is well used by bees and butterflies. The route passes garages, industrial units and gardens, as well as crossing a few busy roads, but nevertheless offers a connectivity for insects that previously didn’t exist.

The linear route also seeks to encourage leisure activities and offers Tallinn residents green active travel routes in and out of the capital’s lively urban centre. It should appeal to commuters and city dwellers alike. It’s been carefully crafted and shows that urbanization and nature don’t need to be mutually exclusive. It is clearly multifunctional.

The Pollinator Highway runs from the western border of Tallinn right up to the footsteps of the Old Town. It’s a popular and attractive feature. Bee Borders line parts of the route and are easy on the eye as well as a great source of food and shelter for pollinators. A mix of grasses, native plants and nectar-rich perennials fill these borders, and eye-catching purple aster, goldenrod, and coneflower are amongst the plants on display

Entomologists from the University of Tartu have been studying the pollinator and plants mix closely. They are particularly interested in how the existing vegetation influences the abundance and variety of pollinator species (to date they have logged 42 different butterfly species and 22 bumblebee species). This will help them better understand which plants are most valuable in the quest to increase pollinator populations. Ultimately the group want to produce a list of optimum pollinator plants to guarantee pollinators have food sources throughout their active life-cycle from early spring until autumn.

There are plans to reduce mowing to just a single September cut and lift, instead of the current two cuts. This will not initially please everyone, some might view the uncut areas as neglected, so there will be interpretation to explain the purpose of the relaxed mowing regime and the contribution this will make to providing wonderful living conditions for urban biodiversity.

The move to convert the high-voltage overhead lines into buried underground cables is an astute one. It makes the route instantly more appealing. In addition the introduction of allotments and community gardens further enhances the value of the route in the lives of local residents.

The environmental community in Estonia recognise that intensive agriculture and habitat loss in rural areas have, if anything, made urban sites even more important. Thus, initiatives like Tallinn’s Pollinator Highway assume greater importance. Urban areas can quickly accommodate nature networks, and well-designed green infrastructure clearly bolsters nature and enhances city living for people on several levels.

The success of the Putukaväil in Tallinn has unleashed improved opportunities to better connect people with nature. Green corridors of this kind are natural stepping stones for pollinators and a fantastic resource for communities and residents’ health and well-being. We should embrace them, and advocate for this multi-beneficial approach across urban Europe.

Find out more :

European Green Capital Award Good Practices – Tallinn – The Pollinator Highway

Learn more on the Putukaväil website

Pesky little helpers

By Athayde Tonhasca

“He could put up with his meaningless office-life, because he never for an instant thought of it as permanent. God knew how or when, he was going to break free of it (…) The types he saw all around him, especially the older men, made him squirm. That is what it meant to worship the money-god! To settle down, to Make Good, to sell your soul for a villa and an aspidistra!” (Keep the Aspidistra Flying, 1936). 

In George Orwell’s (1903-1950) novel, Gordon Comstock leaves a successful career in advertising (‘the rattling of a stick inside a swill bucket’) to become a poet. But Comstock’s literary shortcomings push him slowly and inexorably into poverty, and the idealist and bitter writer pontificates about the materialism, dryness and mediocrity of the English middle class. And nothing could symbolise better society’s predictability and pedestrianism than the common aspidistra, aka bar room plant, iron plant or cast-iron plant (Aspidistra elatior). A native of Japan, the common aspidistra is widely cultivated as a houseplant around the world. Because of its sturdiness and tolerance to neglect, it became a favourite in English homes in Victorian times, although its popularity has since waned a bit.

The once ubiquitous common aspidistra © Nino Barbieri, Wikimedia Commons.

W. F. Harvey (1885-1937), the Quaker author of macabre and horror stories, told the tale of Ferdinand Wilton, who tried unsuccessfully to destroy aspidistras, only to get some creepy just deserts… Image from Tatler magazine, 1930, British Library.

Orwell would be pleased to know that other characters could have embodied dullness and obscurity in Comstock’s social narrative: gnats.

‘Gnat’ is a loose term to refer to small (usually less than 1 cm), unremarkable and poorly known flies in the suborder Nematocera, which include crane flies, mosquitoes, black flies, and midges. Gardeners will be familiar with one particular group: the dark-winged fungus gnats (family Sciaridae). These tiny black flies make a nuisance of themselves by flying erratically and in great numbers around potted plants, often finding their way to rubbish bins, kitchen drains, window panes, and fruit bowls. The adults feed on nectar or on nothing at all (they have very short lives), and the larvae eat mostly fungi or organic matter in damp soil – that’s why potted plants are ideal for them. Fungus gnats are largely harmless, but if their larvae became too abundant, they may start to feed on plants’ tender roots, damaging them or transmitting pathogens. Seedling ‘damping off’ is a sign of possible fungus gnat infestation. Predictably, if you search for ‘gnats’ in the internet, most pages will be focused on ‘how to get rid of’.

Sciara hemerobioides fungus gnats © gailhampshire, Wikimedia Commons.

Fungus gnats may be an occasional headache in households, but these uninvited guests represent a minute portion of their fauna. Besides the 2,500 or so species of Sciaridae, there are more than 4,500 species in the family Mycetophilidae and numerous species from related groups. Most of these fungus gnats live in shady, damp spots under forest canopies, along water courses or wetlands – places offering ideal conditions for their larvae. These permanently moist environments may be great for gnats, but are not so good for most pollinating insects, who require warmer, drier habitats and open spaces. So plants in fungus gnat territory such as Aspidistra spp. have to find alternatives.

Flowers of the common aspidistra are nothing to look at. Oddly shaped, fleshy and coloured with a purple-redish hue, they emerge directly from the rhizome at ground level or are sometimes hidden underneath the litter. People may not even notice their potted aspidistra has bloomed. And no aroma bouquets from this plant: only a faint musty odour, which some people can’t even detect. Everything from this flower gives it a mushroom appearance, so it’s far from ideal to bees and butterflies. And there’s more to put off run-of-the-mill pollinators: to access the pollen, they have to squeeze by a large stigma (the female part of the flower) to reach the pollen-producing stamens tucked underneath; only the smallest insects can do it. You probably can see where this is going.

Flowers from a ca. 50 years-old potted aspidistra © Boervos, Wikimedia Commons.

The common aspidistra and related species cannot self-fertilise, but their pollination mechanism remained a mystery for years. Slugs, snails, springtails and other ground-dwelling invertebrates have been suggested as potential pollen vectors, but none of these candidates were backed up by data. Enter Suetsugu & Sueyoshi (2018), who spent two years investigating the common aspidistra in Kuroshima Island, Japan, where this plant grows wild. Their efforts paid off: they recorded two species of fungus gnats covered in pollen leaving and landing on flowers, and observed the successful development of fruits in gnat-visited flowers. These observations suggest the puzzle has been resolved. The researchers proposed, reasonably, that Aspidistra have evolved flowers that look and smell like fungi, thus becoming irresistible to fungus-eating gnats.

A male dark-winged fungus gnat, a Sciaridae species © John Tann, Wikimedia Commons.

Flies are considered the second most important group of insect pollinators after bees; house flies (Muscidae), blow flies (Calliphoridae), flesh flies (Sarcophagidae) and especially hover flies (Syrphidae) pollinate a range of crop and wild plants. Some flies are essential pollinators in high altitudes, where bees are scarce or absent. Fungus gnats are hardly thought as members of the pollinators club because they don’t seem to have what it takes: they are too small to carry a decent pollen load, their ‘hair’ (bristles) – an important pollen-carrying apparatus – are puny, and they are weak fliers. Yet, pollination by fungus gnats occurs in 20 genera of eight plant families over the world.

Fungus gnats and other small dipteran insects such as midges and drosophilid flies are diverse and abundant, but we know very little about most of them because they are difficult to identify and study in the field. Worse yet, many species are nocturnal, and the flowers they visit are inconspicuous. So just like midge-pollinated cacao and jackfruit, the gnat-pollinated aspidistra suggests there are many discoveries to be made about these pesky little flies.