Category Archives: Flies

Flowers can be assholes – quite literally!

2003-572 s G Bochum

WARNING: There’s a high yuck factor to this post, it’s not for the squeamish or easily offended!

One of my Twitter contacts, Traci Birge in Finland, has been reading Pollinators & Pollination: Nature and Society, and making some very nice comments about it. I had to laugh at this one in which she describes some plants as “assholes” because of the way in which they deceive pollinators into visiting their flowers but offer no reward in return:

If you follow that thread you can see that Traci was closer to the truth than perhaps she realised: there are some plants with flowers that appear to mimic the anuses of dead mammals, particularly in the families Apocynaceae and Araceae. By their smell, texture, colour and hairiness they are fooling flies into visiting the flowers, because assholes, like any mammalian orifice, provide an entry point for maggots of carrion-feeding flies. Sometimes the deception is so great that the flies lay their eggs on these blooms, though of course the maggots starve.

A great example of an anus-mimicking bloom is the Dead Horse Arum (Helicodiceros muscivorus). Check out the image above: if that doesn’t look like a horse’s ass, I don’t know what does!

Other examples might be found within the stapeliads, especially the genus Huernia which often have a thickened annulus to the centre of the flower. However that could also be interpreted as mimicking an open, inflamed wound on the side of an animal:

As I point out in the book, you might imagine that there would be strong natural selection against flies visiting these flowers if they lose fitness by laying eggs on such an unsuitable substrate. But the flowers are tapping into really deep-seated behaviours and clearly the flies can’t distinguish the flowers from the real thing.

This is flower pollination that is far removed from the deliciously perfumed, cute-and-cuddly, heart-warming world of bees and flowers. Isn’t nature wonderful?

All photos from Wikipedia, as follows:

Helicodiceros muscivorus: Göteborgs botaniska trädgård (photographer: Ingemar Johansson) – http://www.mynewsdesk.com/se/pressroom/goteborgs_botaniska_tradgard/image/view/dracunculus-muscivorus-128973, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=19265330

Huernia zebrina: Enzo^ – Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=10963668

Huernia schneideriana: Juan Carlos Fonseca Mata – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=94705877

Pollinators and pollination in the UK: an introductory workshop – 26th August

Jeff WT workshop 2020

The Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire has invited me to run my Introduction to Pollinators and Pollination workshop again this year, but of course it will all be online.  Details for signing up are on the images, or you can follow this link. 

Here’s a description of the workshop:

Pollination of flowers ensures the reproduction of most British wild plants and many of our agricultural crops. This session will provide an introduction to the natural history of pollinators and how they interact with the flowers that they pollinate. The main groups of pollinators will be introduced, with guidance on how to identify them, and their ecology and behaviour will be explored. The session will also consider why conserving these species is so important, followed by a Q and A discussion showing what individuals can do to help ensure their future diversity and abundance.

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

PollinatorsandPollination-frontcover

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
References
Index

 

 

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: https://www.latlong.net/degrees-minutes-seconds-to-decimal-degrees

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] northampton.ac.uk

The other pollinators: some recent videos that don’t focus on bees

The review of the biodiversity of pollinators that I published in 2017 estimated that on average about 18% of animal-pollinated plants within natural communities are specialised on bees. Bees also contribute to the reproduction of many of the plants that have generalist pollination systems, which account for perhaps 50% of plant species on average. But that stills leaves a significant fraction (maybe one third) that are specialised on the “other” pollinators, including flies, beetles, birds, bats, and so forth. There is growing awareness of how important these pollinators are for wild plant and crop pollination, but bees still hog most of the pollinator-related media.

In the last couple of weeks I’ve been sent links to videos that focus on these other pollinators so I thought I’d compile a list that show us something of the true diversity of animals that act as pollen vectors. Please add your own suggestions in the comments:

Elephant shrews, lizards, cockroaches*, crustaceans, and biting midges are covered in this SciShow video (HT Steve Hawkins)

Opossum pollination of a Brazilian plant is featured in this video (HT Felipe Amorim)

Here’s a recorded webinar on bird pollination by Dan Scheiman from Audubon Arkansas

A few videos on bat pollination by Jim Wolfe can be found here and here and here, and this is a short one that’s a supplement to a recent Journal of Applied Ecology paper on cactus pollination by Constance J. Tremlett et al.

The fascinating ecology of skunk cabbage (Symplocarpus foetidus), including fly and possibly beetle pollination, is the topic of this video.

Fly pollination is also highlighted in this short piece by the Natural History Museum, and this one deals with drone flies as managed pollinators for agriculture in New Zealand.

Enjoy!

*Watch out for my report on a newly discovered cockroach-pollinated plant….hopefully coming later this year…..