Category Archives: Gardens

Claims that only 10% – and not 75% – of crops are pollinator dependent are misleading and dishonest

Earlier this week the Genetic Literacy Project site posted an essay entitled ‘10% — not 75% — of crops pollinator-dependent: Our World in Data debunks claims that global food supply is imminently endangered by ‘disappearing’ insects‘. That click-bait title is hugely misleading, some of the purported ‘facts’ are incorrect, and indeed the whole thing reeks of dishonesty and bad faith.

First the misleading title. This ‘debunks’ claim actually compares two different things: 75% of CROPS being dependent on pollinators versus 10% of crop YIELD. However, even if we focus on the 10% claim, a small increase in yield can be the difference between profit and bankruptcy for small-scale farmers. And most of the world’s farmers are small-scale and living on the borderline between loss and break-even. In addition, there’s no acknowledgement of the food production from home gardens, allotments, and community gardens, which is significant but largely unquantified.

Next, by focusing on yield and comparing, say, wind-pollinated wheat with insect-pollinated apples, the article takes no account of the fact that many of these crops that depend to some extent on pollinators mainly provide essential vitamins and minerals – not calories – to diets. When I tweeted about this earlier in the week, one person commented that they describe the insect-pollinated foods as ‘an important source of flavour and colour in our diets, rice and wheat are all well and good, but you do kinda need something more than grey slop to live’. Another said: ‘I’m so glad you mentioned this. I’m sick of reading articles that praise innovations to increase calories, when what we need is better nutrition from vitamins, minerals & fibres’.

Both great points, and well made.

That essay was also factually incorrect when it described roots crops such as carrots or some of the leafy cabbages and lettuces as not requiring pollinators. Many varieties of these crops ARE pollinator dependent: how do they think we get the seed for the next year’s crop?! And there are many crops and varieties that have not been evaluated for their dependency on pollinators: the 75% figure actually refers to the 115 most productive crop plants (Klein et al. 2007).

When I tweeted about the essay I commented that I was very disappointed by ‘Our World in Data’ – they are usually better than this when it comes to the facts. What I hadn’t appreciated at the time was that in fact the Genetic Literacy Project had highjacked the original piece by Hannah Ritchie and reworked it to give it a very different slant*.

This is where it starts to get dishonest and in fact the Genetic Literacy Project (GLP) has form in this area. The Sourcewatch site describes the GLP as ‘a corporate front group that was formerly funded by Monsanto’ with a remit to ‘shame scientists and highlight information helpful to Monsanto and other chemical producers’. In other words it’s heavily tied to Big Agriculture which, of course, would like us to believe that there’s not an issue with declining pollinators, that pesticides and agricultural intensification are our friends, and that Everything Is OK. Read the full account here.

Frankly, the GLP is so tainted that I’d not believe anything that they publish.

Pollinator decline and the role of pollinators in agriculture are complex issues. If you’d like to know more about the importance of pollinators to agriculture, complete with some accurate and objective facts, then there’s a whole chapter devoted to the topic in my book Pollinators & Pollination: Nature and Society.

*Note that I’ve been communicating with Hannah about the root and leaf crop issue and she accepts that this needs to change in the original. She’s also asked the Genetic Literacy Project to take down their version as it contravenes copyright.


Klein, A.-M., Vaissière, B.E., Cane, J.H. et al. (2007) Importance of pollinators in
changing landscapes for world crops. Proceedings of the Royal Society of London B
274: 303–313.

What to do if you have beewolves nesting in your garden? Leave them alone!

Earlier today we had a message from the owner of the AirBnB that we are staying in to let us know that he’s expecting a guy to come and spray pesticide around the house to kill the ‘invasive’ beewolves. The European beewolf (Philanthus triangulum) is a type of wasp in the family Crabronidae that is only distantly related to the typical wasps that you find trying to share your barbecue and beer. As its name suggests, it preys upon bees, but it’s actually a pollinator itself and visits a range of flowers.

I immediately got back to our host and pointed out that beewolves are gentle insects, completely harmless, and less dangerous than the pesticide the company would use to kill them, and that he was wasting his money. He informed us that the pest control company had told him that he needed to control them other wise he’d be ‘over-run’ with them next year!

When I explained to him that this was nonsense, and that the beewolves cause no damage to people or property, he promised to get back to the company to cancel the order, and thanked me for the information. I’m hoping that I’ve made a convert to the cause of insect conservation!

It maddens me that pest control companies are preying on people’s fear of insects to make money in this way. Insects are subjected to enough assaults by human activities without making up spurious reasons for poisoning them.

So if you are lucky enough to have beewolves in your garden, please treat them with respect and watch their fascinating behaviour:

Houseplants & Happiness: join me at the LEAF Houseplant Festival – 30th & 31st May!

One of my earliest exposures to botany was growing houseplants as a teenager, encouraged by my dad who, as I discussed in Pollinators & Pollination: Nature and Society, was a very keen gardener. It was my dad who taught me about rooting cuttings in water, how to germinate seeds, and so forth. These are gifts of knowledge that I will always treasure and which I have passed on to my own offspring.

So I was delighted to accept an invitation to run a workshop at the LEAF Houseplant Festival in Market Harborough that takes place from 30th to 31st May this year. Tickets can be booked by following that link, though be aware that they are limited due to social-distancing regulations, and it’s first come, first served.

The workshop that I am running is called ‘Potting Up’ and will focus on the different kinds of potting media to use, how to tailor your compost to specific types of plants, and so forth. As you might expect, I’ll be using my knowledge of plant ecology to explain why different plants have different requirements, and what those requirements are.

As well as running the workshop, Karin and I will be selling off some of our own collection of houseplants on a ‘Pre-loved Plants’ stall. We are in the process of selling our house in Northampton and we need to downsize!

Finally, I will also have a limited number of copies of Pollinators & Pollination: Nature and Society for sale. If you would like to reserve a signed copy to pick up on the day, please use the Contact form.

I look forward to seeing some of you there: it will be great to actually mix with people, have face-to-face discussions, and interact with an audience that’s in the same room as me!

Online talks and training: here’s a selection of what I offer

Over the past few months I’ve done a large number of online talks for a variety of audiences, including natural history and gardening societies, beekeeping groups, private companies, university estates departments, and ecological consultancies. I thought it would be useful to provide a list of what I offer, with a short description. All talks are accessible and understandable to a broad audience, and can be tailored to the individual needs of the group:

Pollinators & Pollination: Nature and Society is an introduction to the importance of pollinators and the pollination services that they provide to both wild and crop plants. The name, of course, reflects that of my recent book.

The Politics of Pollination is an account of how society (governments, organisations and individuals) has responded to the current “pollination crisis” (if that’s what it actually is…)

Bees in Cities: an Introduction to Urban Pollinators focuses on the positive roles that urban environments can play for pollinators, and the potential threats of city living.

Pollinators in Gardens gives practical advice on how to make your garden “pollinator friendly”.

Pollinator Conservation: Threats and Opportunities describes how and why pollinators are declining and what we can do about it at the individual and societal level.

Habitat Creation and Management for Pollinators gives an introduction to how NGOs, estates departments, consultancies, and so forth, can effectively support pollinators in ways that go beyond just planting flowers and putting up a few “bee hotels”.

To Be a Flower is an introduction to how flowers function and the ways in which they manipulate the behaviour of their pollinators to ensure reproduction.

Darwin’s Unrequited Isle: a Personal Natural History of Tenerife describes some of the field work that we’ve been doing on this most fascinating of the Canary Islands.

Biodiversity: What Is It and Why Should We Care? gives a very general overview of the topic of biodiversity and ecosystem services.

Talks typically last for around 50 minutes, following which I’m happy to answer questions and discuss any issues that have arisen. I also offer a half- or full-day of training for those organisations that need more depth, for example ecological consultancies. Note that I charge for all of my talks and training. If you would like to enquire about any of this, please use the form on the Contact page.

Plant-pollinator networks in Australian urban bushland remnants are not structurally equivalent to those in residential gardens – a new study just published

Towns and cities are ecologically complex environments where nature finds a home in all sorts of places, including both highly artificial gardens created by people, and the fragments of natural environment left behind when developments are built. In a new study that I’ve co-authored with Australian researcher Kit Prendergast we’ve for the first time compared and contrasted the pollinators, and the plants that they visit, in urban settings in the the biodiversity hotspot of Western Australia. Full disclosure: the field work was all done by Kit as part of her PhD. I just acted as an “adopted supervisor” (her words!) to help with data analysis and writing up of the work.

I think that it’s a great study, not least because it really highlights just how different gardens are to remnant natural vegetation. If we are to maintain the maximum possible pollinator diversity, and associated pollination services, we need to retain as much remnant vegetation as possible when designing and building new developments. Gardens alone are not enough.

The study details are:

Prendergast, K.S. & Ollerton, J. (2021) Plant-pollinator networks in Australian urban bushland remnants are not structurally equivalent to those in residential gardens. Urban Ecosystems

The abstract is below; if you’d like a PDF of the paper please use the form on the Contact page.


Urbanisation is a prominent and increasing form of land-use change, with the potential to disrupt the interactions between pollinators such as bees and the flowering plants that they visit. This in turn may cause cascading local extinctions and have consequences for pollination services. Network approaches go beyond simple metrics of abundance and species richness, enabling understanding of how the structure of plant-pollinator communities are affected by urbanisation. Here we compared pollination networks between native vegetation (bushland) remnants and residential gardens in the urbanised region of the southwest Australian biodiversity hotspot. Across fourteen sites, seven per habitat, plant-bee visitor networks were created from surveys conducted monthly during the spring-summer period over two years. Extinction slope (a measure of how extinctions cascade through the network), and network robustness and nestedness were higher for bushland remnants, suggesting that networks in bushland remnants had greater functional integrity, but if disrupted, more cascading extinctions could occur. In contrast, niche overlap between pollinators was higher in residential gardens, suggesting greater competition for resources. Most species-level properties did not differ between habitats, except for normalised degree, which was higher in bushland remnants. In conclusion, it appears that pollination networks in managed residential gardens are not structurally equivalent with those in bushland remnants. This has implications for conservation of wild bee assemblages in this biodiversity hotspot, and suggests removal of remnant native vegetation for residential development could disrupt the integrity of plant-pollinator assemblages.

Finally, a physical copy of my book!

Yesterday I was delighted to finally receive an advance copy of my book Pollinators & Pollination: Nature and Society! It’s been over three years in the writing and production, much longer than I had anticipated. But, as I describe in its pages, the book is the culmination of >50 years of experience, study and research. So perhaps three years isn’t so bad…

If you’re interested in buying a copy you can order it direct from Pelagic Publishing and from most of the large online booksellers. Let me know what you think.

The chapter titles for my book: Pollinators & Pollination: Nature and Society

A few people have asked me about what’s covered in my book which is being published by Pelagic and is currently in production. Here’s the chapter titles:


1         The importance of pollinators and pollination                               

2         More than just bees: the diversity of pollinators                           

3         To be a flower                                                                                               

4         Fidelity and promiscuity in Darwin’s entangled bank                 

5         The evolution of pollination strategies                                              

6         A matter of time: from daily cycles to climate change                 

7         Agricultural perspectives                                                                        

8         Urban environments                                                                                  

9         The significance of gardens                                                                    

10      The shifting fates of pollinators                                                            

11      New bees on the block                                                                              

12      Managing, restoring and connecting habitats                                 

13      The politics of pollination                                                                        

14      Studying pollinators and pollination                                                  

As you can see it’s a very wide-ranging overview of the subject, and written to be accessible to both specialists and non-specialists alike. To quote what I wrote in the Preface:

“While the book is aimed at a very broad audience, and is intended to be comprehensible to anyone with an interest in science and the environment, and their intersection with human societies, I hope it will also be of interest to those dealing professionally with plants and pollinators. The subject is vast, and those working on bee or hoverfly biology, for example, or plant reproductive ecology, may learn something new about topics adjacent to their specialisms. I certainly learned a lot from writing the book.”

The book is about 100,000 words in length, lots of illustrations, and there will be an index. My copy editor reckons there’s 450 references cited, though I haven’t counted. I do know that they run to 28 pages in the manuscript, and that’s with 11pt text. All going well it will be published before Christmas.

Get a 30% discount if you pre-order my new book Pollinators & Pollination: Nature and Society


In the next few months my new book Pollinators & Pollination: Nature and Society will be published.  As you can imagine, I’m very excited! The book is currently available to pre-order: you can find full details here at the Pelagic Publishing website.  If you do pre-order it you can claim a 30% discount by using the pre-publication offer code POLLINATOR.

As with my blog, the book is aimed at a very broad audience including the interested public, gardeners, conservationists, and scientists working in the various sub-fields of pollinator and pollination research. The chapter titles are as follows:

Preface and Acknowledgements
1. The importance of pollinators and pollination
2. More than just bees: the diversity of pollinators
3. To be a flower
4. Fidelity and promiscuity in Darwin’s entangled bank
5. The evolution of pollination strategies
6. A matter of time: from daily cycles to climate change
7. Agricultural perspectives
8. Urban environments
9. The significance of gardens
10. Shifting fates of pollinators
11. New bees on the block
12. Managing, restoring and connecting habitats
13. The politics of pollination
14. Studying pollinators and pollination



A pollinator to watch out for in your gardens: the Red-girdled Mining Bee – UPDATED

Last week, during one of my lockdown garden pollinator surveys, I spotted a bee visiting Germander Speedwell (Veronica chamaedrys) in the garden that I didn’t recognise. It initially confused me as it looked superficially like a Blood Bee in the genus Sphecodes. However the bee was clearly collecting pollen, which Sphecodes spp., being cleptoparasites, don’t do. A quick check in Steven Falk’s Field Guide to the Bees of Great Britain and Ireland and a look at Steven’s Flickr site, suggested that it was almost certainly the Red-girdled Mining Bee (Andrena labiata), which is frequently associated with Germander Speedwell.

I posted this video on Twitter and Steven kindly confirmed my identification:

The Red-girdled Mining Bee is considered “Nationally Scarce” and it has a scattered and southerly distribution, as you can see from the map above, which is from the National Biodiversity Network Atlas account for the species. It’s only recorded from about half a dozen sites in Northamptonshire according to Ryan Clark, the County Bee Recorder. However Steven tells me that it’s being seen more and more frequently in gardens, and indeed just the other day Sarah Arnold, who is also carrying out surveys, emailed me to say that she had spotted it in her garden in Kent.

So this is a bee that’s definitely one to look out for, especially if you have Germander Speedwell growing.

UPDATE: I should of course have also given a link to the BWARS account for this species, and mentioned that confirmed or suspected observations can be uploaded to iRecord.

Garden plant-pollinator surveys: progress so far

The network of pollination ecologists and insect specialists who have confirmed that they are surveying plant-pollinator networks in their gardens now stands at 50. As the map above shows, most are in the UK, Ireland and mainland Europe, but the Americas are also becoming well represented, we have a couple of people surveying in North Africa, and three in Australia. An x-y plot of the coordinates of the gardens shows the spread a little better:

Some people have started to send me data already, which is great; if you’re surveying and haven’t let me know your latitude and longitude, please do so, preferably decimalised – you can convert degrees/minutes/seconds to decimal here:

I’ve managed 13 formal 15 minute surveys so far, plus have a few ad hoc observations that I am keeping separate, and I will be continuing my data collection for the foreseeable future. I’ve started playing with the data as you can see below. This is a plot made using the bipartite package in R, with plants to the left and pollinators to the right. The size of the bars is proportional to the number of pollinators/plants a taxon connects to. In the plants you can immediately see the dominance of apple (Malus domestica) and greengage (Prunus domestica), which attract a wide variety of insects to their flowers. Of the pollinators, the hairy-footed flower bee (Anthophora plumipes) and dark-edged beefly (Bombylius major) are especially common and generalist in their flower visits. It will be really interesting to see how this changes over the season, and how our fruit and vegetables are connected into the wider network via pollinators that they share with the ornamental and native plants.

If you are experienced at surveying pollinators and want to get involved, follow that first link and check out the protocol and FAQs, and please do email me: jeff.ollerton [at]