Category Archives: Pollination

Why are bees like Bactrian camels? Because they both have two humps!

It was eminent bee biologist Charles Michener who first* pointed out that there was something odd about the global distribution of bees. In his 1979 paper Biogeography of the bees he writes:

“unlike many groups which abound in the tropics, bees attain their greatest abundance in warm temperate areas”

Think about that for a moment: in contrast to most other groups of insects, birds, mammals, flowering plants, fish, indeed the majority of the Earth’s biodiversity, bees are NOT generally at their most species rich in tropical areas. Rather, we have to move north and south of the equator to find them at their highest diversity. This is an odd pattern of distribution for such a successful (> 20,000 species), globally widespread and ecologically important group of organisms.

Some 15 years ago I was inspired by Michener’s comments when, together with colleagues Steve Johnson and Andrew Hingston, we wrote a chapter called Geographical variation in diversity and specificity of pollination systems for the 2006 Waser & Ollerton edited volume Plant-pollinator Interactions: from Specialization to Generalization. In that chapter we presented a rough analysis of how bee diversity per unit area in different countries changes with latitude. This, and a follow-up that appeared in my 2017 Annual Review of Ecology, Evolution and Systematics paper, confirmed Michener’s view that there’s an unusual relationship between bee diversity and latitude, with peak species richness outside of the tropics, in warm, dry environments.

What I really hoped over this time was that some serious bee biologists would follow up Michener’s insights and produce a full analysis of how bee diversity changes across the planet. Yesterday that hope was realised when Michael Orr, Alice Hughes, Douglas Chesters, John Pickering, Chao-Dong Zhu and John Ascher published the first analysis of bee diversity across the whole planet, and its underlying causes, in their open-access paper Global Patterns and Drivers of Bee Distribution.

Their analyses are based on a data set of >5,800,000 records of where bees occur and it’s been an incredible achievement to bring all of that together into a planet-wide view of where bees are found, and why. I highly recommend that you download and read it, it’s an impressive piece of work.

What have camels got to do with all of this? Well, as the authors show in their paper (from which the image above is taken), if you graph up the increase in bee species richness with latitude from the poles in each hemisphere, you get two humps at about 35 degrees north and south of the equator: like a Bactrian camel. In contrast, as I noted above, if you were to do the same for for most other species you’d get a single hump at the equator: like a dromedary camel.

One of the key drivers of this bimodal pattern seems to be the amount of rainfall in an environment – bees do not like it too wet, in contrast to their relatives the ants which do show the more typical tropical peak in diversity. As the authors put it:

“humidity may play a key role in limiting bee distribution, such as through spoilage of pollen resources”

One of the implications of this for the biogeography of plant-pollinator interactions is that we might expect there to be a greater diversity of different types of pollinators in areas where bees are not so abundant. And indeed that is exactly what we find: in that Ollerton, Johnson and Hingston book chapter I mentioned we showed that there’s a step-change in the diversity of functionally specialised pollination systems as one moves from the sub-tropics into the tropics. There could be many reason for that but I suspect that one is a relative lack of bees compared to the number of plants species; thus you get tropical “oddities” such as specialised cockroach pollination in some plants.

Orr et al.’s paper is a milestone in bee biogeography and opens up new opportunities for conserving these insects, and their vital relationships with the flowering plants. To give just one example: these analyses provide a framework for predicting bee diversity hotspots in parts of the world that have been poorly explored by bee taxonomists, but which are nevertheless severely threatened by habitat degradation and conversion to agriculture. It could also be used for predicting how climate change might affect future bee distributions, especially in parts of the world that are expected to become wetter. I’m looking forward to seeing how the team’s work develops in the future.

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*It’s always risky to state “first”, but Michener was certainly the first that I am aware of. Let me know if you’ve come across any precedents.

SCAPE 2020 by the numbers

Last Friday to Sunday I hosted the annual Scandinavian Association for Pollination Ecology (SCAPE) conference virtually. This is my first opportunity to report back as I took some time off and then tried to catch up with other tasks.

Running any scientific conference is hard work, and virtual ones are no exception! On Monday I was exhausted after a marathon long weekend of three 10-hour days in front of a computer chairing sessions, queuing up speakers and their talks, and generally making sure things ran as smoothly as possible. Of course before that there were literally weeks of preparation, and since then I have been doing follow up work of responding to emails, sending out certificates and receipts, etc.

It’s been quite a job and I couldn’t have done it with the help of my wife Karin (especially for the loan of her office space in the garden) and also Yannick Klomberg who was working on the website, dealing with the posters, etc., all on top of having a week old baby and his partner to look after! In addition I’m grateful to Paul Egan who ran the SCAPE Twitter account, and the session Chairs, keynote speakers, and participants who contributed to a really amazing conference. Our technical support crew from the University of Northampton were great too.

It was the largest SCAPE meeting so far held, no doubt because it was the first to be carried out virtually, with 352 participants from 41 countries listening to and chatting about 92 talks and viewing 39 posters. We also ran several well-attended evening discussion and poster sessions.

Long-standing SCAPEr Marcos Mendez kept a log of the number of participants in each of the sessions and I’ve graphed the data below, showing the broad themes of each group of sessions:

It’s pleasing to see that attendance was reasonably consistent over the course of the long weekend and that there was interest across the full spectrum of themes. The one downward blip was in session 5, which I can only surmise was due to it being the final session on Friday between 17:25 and 18:25.

As is traditional at SCAPE we announced the host of next year’s meeting at the very end. I’m delighted to announce that SCAPE 2021, the 35th annual meeting, will be held for the first time in Poland, where Marcin Zych will be the host. “Wider Scandinavia” just got wider….

SCAPE 2020 – pollinators & pollination conference: here’s the programme

There’s still a few hours left in which to register to attend the SCAPE 2020 pollinators and pollination conference. Follow the links on the website: https://scape-pollination.org/

The programme is more or less finalised and is shown below. We have an amazing range of topics being presented from both established and early career researchers, including two keynote lectures, plus posters. It’s going to be a very exciting weekend of science!

PROGRAMME

Talk types:

K = Keynote

ST = Standard (10 minutes talk + 5 for questions)

F = Flash talk (5 minutes, no questions)

Friday 6th November – all timings are GMT (London) time

TimingTypeNameTitleRef
09.00 –09.15 Jeff OllertonOpen conference and welcome 
09.15 –10.15KLynn DicksUnderstanding the risks to human well-being from pollinator declineK.01
10.15 –10.30 Comfort breakTime to top up your coffee 
Session 1 Chair: Jeff OllertonAgriculture – 1 
10.30 – 10.45STKe ChenIndirect and additive effects of arbuscular mycorrhizal fungi on insect pollination and crop yield of raspberry under different fertilizer levels1.01
10.45 – 11.00STJulia OstermanEnhancing mason bee populations for sweet cherry pollination1.02
11.00 – 11.15STIdan KahnonitchViral distributions in bee communities: associations to honeybee density and flower visitation frequency1.03
11.15 – 11.30STAnna Birgitte MilfordWho takes responsibility for the bees?1.04
11.30 – 11.45STEmma GardnerBoundary features increase and stabilise bee populations and the pollination of mass-flowering crops in rotational systems1.05
11.45 – 12.00STStephanie MaherEvaluating the quantity and quality of resources for pollinators on Irish farms1.06
12.00 –12.05FThomas TimberlakePollinators and human nutrition in rural Nepal: experiences of remote data collection during a global pandemic1.07
12.05 –12.15 Comfort break  
Session 2 Chair: Jane StoutAgriculture – 2 
12.15 – 12.30STMichael ImageThe impact of agri-environment schemes on crop pollination services at national scale2.01
12.30 – 12.45STNicola TommasiPlant – pollinator interactions in sub-Saharan agroecosystems2.02
12.45 – 13.00STTal ShapiraThe combined effects of resource-landscape and herbivory on pollination services in agro-ecosystems2.03
13.00 – 13.15STMárcia Motta MauésDespite the megadiversity of flower visitors, native bees are essential to açai palm (Euterpe oleracea Mart.) pollination at the Amazon estuary2.04
13.15 – 13.30 STSabrina RondeauQuantifying exposure of bumblebee queens to pesticide residues when hibernating in agricultural soils2.05
13.30 –13.35 FMaxime EeraertsLandscapes with high amounts of mass-flowering fruit crops reduce the reproduction of two solitary bees2.06
13.35 – 13.40FPatricia Nunes-SilvaCrop domestication, flower characteristics and interaction with pollinators: the case of Cucurbita pepo (Cucurbitaceae)2.07
13.40 – 14.30 Lunch break  
Session 3 Chair: Mariano DevotoNetworks and communities 
14.30 – 14.45STKit PrendergastPlant-pollinator networks in Australian urban bushland remnants are not structurally equivalent to those in residential gardens3.01
14.45 – 14.50FKavya MohanStructure of plant-visitor networks in a seasonal southern Indian habitat3.02
14.50 – 14.55FOpeyemi AdedojaAsynchrony among insect pollinator groups and flowering plants with elevation3.03
14.55 – 15.10STYael MandelikRangeland sharing by cattle and bees: moderate grazing does not impair bee communities and resource availability3.04
15.10 – 15.25STFelipe Torres-VanegasLandscape change reduces pollen quality indirectly by shifting the functional composition of pollinator communities3.05
15.25 – 15.40STIsabela Vilella-ArnizautQuantifying plant-pollinator interactions in the Prairie Coteau3.06
15.40 – 15.55 Comfort break  
Session 4 Chair: Nina SletvoldConservation perspectives – 1 
15.55 – 16.10STLise RoparsSeasonal dynamics of competition between honeybees and wild bees in a protected Mediterranean scrubland4.01
16.10 – 16.25STPhilip DonkersleyA One-Health model for reversing honeybee (Apis mellifera L.) decline4.02
16.25 – 16.40STNicholas TewNectar supply in gardens: spatial and temporal variation4.03
16.40 – 16.55STPeter GraystockThe effects of environmental toxicants on the health of bumble bees and their microbiomes4.04
16.55 – 17.10STHauke KochFlagellum removal by a heather nectar metabolite inhibits infectivity of a bumblebee parasite4.05
17.10 – 17.25 Comfort break  
Session 5 Chair: Anders NielsenConservation perspectives – 2 
17.25 – 17.40STMiranda BanePollinators on Guernsey and a Pesticide-free Plan5.01
17.40 – 17.55STJamie WildmanReintroducing Carterocephalus palaemon to England: using the legacy of a locally extinct butterfly as a (morpho)metric of future success5.02
17.55 – 18.10STSjirk GeertsInvasive alien Proteaceae lure some, but not other nectar feeding bird pollinators away from native Proteaceae in South African fynbos5.03
18.10 – 18.25STSissi Lozada GobilardHabitat quality and connectivity in kettle holes enhance bee diversity in agricultural landscapes5.04
18.25 –18.45 Comfort break  
18.45 – 23.59 Themed discussion rooms open  

Saturday 7th November – all timings are GMT (London) time

TimingTypeNameTitleRef
08.55 – 09.00 Jeff OllertonReminders and announcements 
Session 6 Chair: Jeff OllertonConservation perspectives – 3 
09.00 – 09.15STPaolo BiellaThe effects of landscape composition and climatic variables on pollinator abundances and foraging along a gradient of increasing urbanization6.01
09.15 – 09.30STJames RodgerPotential impacts of pollinator declines on plant seed production and population viability6.02
09.30 – 09.45STEmilie EllisMoth assemblages within urban domestic gardens respond positively to habitat complexity, but only at a scale that extends beyond the garden boundary6.03
09.45 – 10.00STSamuel BoffNovel pesticide class impact foraging behaviour in wild bees6.04
10.00 – 10.15 Comfort breakTime to top up your coffee 
Session 7 Chair: Jon AgrenConservation perspectives – 4 
10.15 – 10.20FMaisie BrettThe impacts of invasive Acacias on the pollination networks of South African Fynbos habitats7.01
10.20 – 10.25FJoseph MillardGlobal effects of land-use intensity on local pollinator biodiversity7.02
10.25 – 10.30FSusanne ButschkauHow does land-use affect the mutualistic outcomes of bee-plant interactions?7.03
10.30 – 10.35FElżbieta Rożej-PabijanImpact of wet meadow translocation on species composition of bees (Hymenoptera: Apoidea: Apiformes)7.04
10.35 – 10.40FLorenzo GuzzettiMay urbanization affect the quality of pollinators diet? A case-study from Milan, Italy.7.05
10.40 – 10.45FEmiliano PioltelliFunctional traits variation in two bumblebee species along a gradient of landscape anthropization7.06
10.45 – 11.00 Comfort break  
Session 8 Chair: Marcos MendezPollinator behaviour – 1 
11.00 – 11.15STHema SomanathanForaging on left-overs: comparative resource use in diurnal and nocturnal bees8.01
11.15 – 11.30STSajesh VijayanTo leave or to stay? Answers from migratory waggle dances in Apis dorsata8.02
11.30 – 11.45STBalamurali MGSDecision making in the Asian honeybee Apis cerana is influenced by innate sensory biases and associative learning at different spatial scales8.03
11.45 – 12.00STGemma VillagomezResource intake of stingless bee colonies in a tropical ecosystem in Ecuador8.04
12.00 – 12.15STOla OlssonPollen analysis   using deep learning – better, stronger, faster8.05
12.15 – 13.00 Lunch break  
Session 9 Chair: Magne FribergPollinator behaviour – 2 
13.00 – 13.15STShuxuan Jing‘Interviewing’ pollinators in the red clover field: foraging behaviour9.01
13.15 – 13.30STOcéane BartholoméeHow to eat in the shade? Bumblebees’ behavior in partially shaded flower strips9.02
13.30 – 13.45STManuela GiovanettiMegachile sculpturalis: insights on the nesting activity of an alien bee species9.03
13.45 – 14.00    STZahra MoradinourThe allometry of sensory system in the butterfly Pieris napi9.04
14.00 – 14.05FPierre TichitNew insights into the visual ecology of bees9.05
14.05 – 14.10FFabian RuedenauerDoes pollinator dependence correlate with the nutritional profile of pollen in plants?9.06
14.10 – 14.15FHannah BurgerFloral signals involved in host finding by nectar-foraging social wasps9.07
14.15 – 14.30 Comfort break  
Session 10 Chair: ‪ Amy ParachnowitschFloral scent 
14.30 – 14.45STHerbert BraunschmidDoes the rarity of a flower´s scent phenotype in a deceptive orchid explain its pollination success?10.01
14.45 – 15.00STYedra GarcíaEcology and evolution of floral scent compartmentalization10.02
15.00 – 15.15STManoj Kaushalya RathnayakeDoes floral scent changes with pollinator syndrome?10.03
15.15 – 15.20FHanna ThostemanThe chemical landscape of Arabis alpina10.04
15.20 – 15.25FLaura S. HildesheimPatterns of floral scent composition in species providing resin pollinator rewards10.05
15.25 – 15.30FChristine Rose-SmythDoes Myrmecophila thomsoniana (Orchidaceae) use uncoupled mimicry to obtain pollination? 10.06
15.30 – 15.45 Comfort break  
Session 11 Chair: Renate WesselinghPollination ecology and floral evolution – 1 
15.45 – 16.00STRachel SpiglerAdaptive plasticity of floral display and its limits11.01
16.00 – 16.15STWendy SemskiIndividual flowering schedules and floral display size in monkeyflower: a common garden study11.02
16.15 – 16.30STCarlos MartelSpecialization for tachinid fly pollination and the evolutionary divergence between varieties of the orchid Neotinea ustulata11.03
16.30 – 16.45STMarcela Moré  Different points of view in a changing world: The tobacco tree flowers through the eyes of its pollinators in native and non-native ranges11.05
16.45 – 17.00 Comfort break  
17.00 – 18.00 Poster discussion rooms openA chance to talk with the author of the posters 
18.00 – 23.59 Themed discussion rooms open   

Sunday 8th November – all timings are GMT (London) time

TimingTypeNameTitleRef
08.55 – 09.00  Jeff OllertonReminders and announcements 
09.00 – 10.00KScott ArmbrusterPollination accuracy explains the evolution of floral movementsK.02
10.00 – 10.15 Comfort breakTime to top up your coffee 
Session 12 Chair: Jeff OllertonPollination ecology and floral evolution – 2 
10.15 – 10.30STKazuharu OhashiThree options are better than two: complementary nature of different pollination modes in Salix caprea12.01
10.30 – 10.45STJames CookWhy size matters in fig-pollinator mutualisms12.02
10.45 – 11.00STYuval SapirWithin-population flower colour variation: beyond pollinator-mediated selection12.03
11.00 – 11.15STHenninge Torp BieFlower visitation of the Sticky catchfly (Viscaria vulgaris) on isles within isle.12.04
11.15 – 11.20    
11.20 – 11.30 Comfort break  
Session 13 Chair: Yuval SapirPollination ecology and floral evolution – 3 
11.30 – 11.45STJonas KupplerImpacts of drought on floral traits, plant-pollinator interactions and plant reproductive success – a meta-analysis13.01
11.45 – 12.00STCarmen Villacañas de CastroCost/benefit ratio of a nursery pollination system in natural populations: a model application13.02
12.00 – 12.15STAnna E-VojtkóFloral and reproductive plant functional traits as an independent axis of plant ecological strategies13.03
12.15 – 12.30STCamille CornetRole of pollinators in prezygotic isolation between calcicolous and silicicolous ecotypes of Silene nutans13.04
12.30 – 12.45STCourtney GormanPhenological and pollinator-mediated isolation among selfing and outcrossing Arabidopsis lyrata populations13.05
12.45 – 13.45 Lunch break  
Session 14 Chair: Rocio BarralesPollination ecology and floral evolution – 4 
13.45 – 14.00STDanae LainaGeographic differences in pollinator availability in the habitats shape the degree of pollinator specialization in the deceptive Arum maculatum L. (Araceae)14.01
14.00 – 14.15  STEva GfrererIs the inflorescence scent of Arum maculatum L. (Araceae) in populations north vs. south of the Alps locally adapted to a variable pollinator climate?14.02
14.15 – 14.30STKelsey ByersPollinators and visitors to Gymnadenia orchids: historical and modern data reveal associations between insect proboscis and floral nectar spur length14.03
14.30 – 14.45STNina JirgalOrientation matters: effect of floral symmetry and orientation on pollinator entry angle14.04
14.45 – 15.00STAlice FairnieUnderstanding the development, evolution and function of the bullseye pigmentation pattern in Hibiscus trionum14.05
15.00 – 15.15 Comfort break  
Session 15 Chair: Maria Clara CastellanosPollination ecology and floral evolution – 5 
15.15 – 15.30STJon ÅgrenOn the measurement and meaning of pollinator-mediated selection15.01
15.30 – 15.45STKatarzyna RoguzPlants taking charge: Autonomous self-pollination as response to plants-pollinator mismatch in Fritillaria persica15.02
15.45 – 16.00STMario Vallejo-MarinBees vs flies: Comparison of non-flight vibrations and  implications for buzz pollination15.03
16.00 – 16.15STAgnes DellingerLinking flower morphology to pollen-release dynamics: buzz-pollination in Melastomataceae15.04
16.15 – 16.30STLucy NevardAre bees and flowers tuned to each other? Variation in the natural frequency of buzz-pollinated flowers.15.05
16.30 – 16.35 FGabriel Chagas LanesAn investigation of pollen movement and release by poricidal anthers using mathematical billiards15.06
16.35 – 16.40FRebecca HoeferThe magnitude of water stress and high soil nitrogen decreases plants reproductive success15.07
16.40 – 16.45FMarta BarberisMay ecotonal plants attract less efficient pollinators to stay on the safe side?15.08
16.45 – 17.00 Comfort break  
Session 16 Chair: Jeff OllertonPollination ecology and floral evolution – 6 
17.00 – 17.15STGabriela DoriaPetal cell shape and flower-pollinator interaction in Nicotiana16.01
17.15 – 17.30STNathan MuchhalaThe long stems characteristic of bat-pollinated flowers greatly reduce bat search times while foraging16.02
17.30 – 17.35FJuan Isaac Moreira-HernándezDifferential tolerance to heterospecific pollen deposition in sympatric species of bat-pollinated Burmeistera (Campanulaceae: Lobelioideae)16.03
17.35 – 17.40FJuan José Domínguez-DelgadoDoes autopolyploidy contribute to shape plant-pollinator interactions?16.04
17.40 – 17.45FCaio Simões BallarinHow many animal-pollinated plants are nectar-producing?16.05
17.45 – 17.50FAna Clara IbañezConcerted evolution between flower phenotype and pollinators in Salpichroa (Solanaceae)16.06
17.50 – 18.15 Jeff OllertonPrize announcements, conference handover and close.16.07

Cockroaches as pollinators: a new example just published

When you think of the word “pollinator” what comes to mind? For most people it will be bees, particularly the western honeybee (Apis mellifera). Some might also think of hoverflies, butterflies, moths, bats, hummingbirds…..but cockroaches?! The first published example that I know of which demonstrated that the flowers of a plant are specialised for cockroach pollination is from the mid-1990s. Since then only a handful of well documented cases have come to light, but there are undoubtedly more out there waiting to be discovered, particularly in the wet tropics. Most of the c. 4,600 species of cockroaches are nocturnal, and cockroach-pollinated flowers tend to open at night, which is one reason why they are under documented.

In a new study, published this week in the American Journal of Botany, a team of Chinese, German and British biologists has shown that a species of Apocynaceae from China is the first known example of cockroach pollination in that large family. Here’s the reference with a link to the study; if anyone wants a copy please email me:

Xiong, W., Ollerton, J., Liede-Schumann, S., Zhao, W., Jiang, Q., Sun, H. Liao, W. & You, W. (2020) Specialized cockroach pollination in the rare and endangered plant Vincetoxicum hainanense (Apocynaceae, Asclepiadoideae) in China. American Journal of Botany (in press)

The abstract for the paper follows:

Premise

Species of Apocynaceae are pollinated by a diverse assemblage of animals. Here we report the first record of specialized cockroach pollination in the family, involving an endangered climbing vine species, Vincetoxicum hainanense in China. Experiments were designed to provide direct proof of cockroach pollination and compare the effectiveness of other flower visitors.

Methods

We investigated the reproductive biology, pollination ecology, pollinaria removal, pollinia insertion, and fruit set following single visits by the most common insects. In addition, we reviewed reports of cockroaches as pollinators of other plants and analyzed the known pollination systems in Vincetoxicum in a phylogenetic context.

Results

The small, pale green flowers of V. hainanense opened during the night. The flowers were not autogamous, but were self‐compatible. Flower visitors included beetles, flies, ants and bush crickets, but the most effective pollinator was the cockroach Blattella bisignata, the only visitor that carried pollen between plants. Less frequent and effective pollinators are ants and Carabidae. Plants in this genus are predominantly pollinated by flies, moths and wasps.

Conclusions

Globally, only 11 plant species are known to be cockroach‐pollinated. Because their range of floral features encompass similarities and differences, defining a “cockroach pollination syndrome” is difficult. One commonality is that flowers are often visited by insects other than cockroaches, such as beetles, that vary in their significance as pollinators. Cockroach pollination is undoubtedly more widespread than previously thought and requires further attention.

Magnolia, Mississippi, and American politics: a guest post

This is a short guest post by Dr Peter Bernhardt who recently retired as a professor at St Louis University and continues to be active in pollination biology.

Each of the 50 American states has its own flag. On Election Day in November 2020 the citizens of the state of Mississippi will vote on whether they want a new flag featuring the flower of their state tree, the southern magnolia or bull bay (Magnolia grandiflora). Of the eight Magnolia species native to the continental United States six have natural distributions including the state of Mississippi.

By voting in the magnolia flag Mississippians drop its 126-year old predecessor, which incorporated an emblem (the stainless banner) adopted by southern states during the American Civil War (1861-1865). This will also mean that Mississippi will be the only state with a flag depicting a flower in which tepals, stamens and carpels are all arranged in a continuous spiral and is pollinated by beetles (see Leonard Thien’s study published in 1974). 

The popularity of M. grandifora far exceeds silviculture in the American south as successful exports stretch over two centuries and its cultigens are found as far as China and Australia.

Politics in America have turned floral in the last months of 2020: kamala, as in vice-presidential candidate Kamala Harris, is an Indian word for sacred lotus (Nelumbo nucifera). 

To which Jeff adds: the flag above is the one that Mississippi citizens will be voting on – follow the link at the start to get the full story of the competition that was run to select a new flag.

Just published: An empirical attack tolerance test alters the structure and species richness of plant–pollinator networks

The latest paper from Paolo Biella‘s PhD work, on which I collaborated and that I’ve discussed before on the blog, has just been published in the journal Functional Ecology. It’s entitled “An empirical attack tolerance test alters the structure and species richness of plant–pollinator networks“. The paper presents more of Paolo’s work showing how the experimental removal of the floral resources provided by the more generalised plants in a community can significantly (and negatively) affect the patterns of interaction between flowers and pollinators that we observe. It’s another piece of evidence that demonstrates how important it is to not neglect the common plants that attract a lot of flower visitors when considering how to manage a habitat.

If anyone has trouble accessing the PDF, drop me a line and I will send it to you.

Here’s the reference:

Biella, P., Akter, A., Ollerton, J., Nielsen, A. & Klecka, J. (2020) An empirical attack tolerance test alters the structure and species richness of plant-pollinator networks. Functional Ecology DOI: 10.1111/1365-2435.13642

Here’s the abstract:

Ecological network theory hypothesizes that the structuring of species interactions can convey stability to the system. Investigating how these structures react to species loss is fundamental for understanding network disassembly or their robustness. However, this topic has mainly been studied in‐silico so far.

Here, in an experimental manipulation, we sequentially removed four generalist plants from real plant–pollinator networks. We explored the effects on, and drivers of, species and interaction disappearance, network structure and interaction rewiring. First, we compared both the local extinctions of species and interactions and the observed network indices with those expected from three co‐extinction models. Second, we investigated the trends in network indices and rewiring rate after plant removal and the pollinator tendency at establishing novel links in relation to their proportional visitation to the removed plants. Furthermore, we explored the underlying drivers of network assembly with probability matrices based on ecological traits.

Our results indicate that the cumulative local extinctions of species and interactions increased faster with generalist plant loss than what was expected by co‐extinction models, which predicted the survival or disappearance of many species incorrectly, and the observed network indices were lowly correlated to those predicted by co‐extinction models. Furthermore, the real networks reacted in complex ways to plant removal. First, network nestedness decreased and modularity increased. Second, although species abundance was a main assembly rule, opportunistic random interactions and structural unpredictability emerged as plants were removed. Both these reactions could indicate network instability and fragility. Other results showed network reorganization, as rewiring rate was high and asymmetries between network levels emerged as plants increased their centrality. Moreover, the generalist pollinators that had frequently visited both the plants targeted of removal and the non‐target plants tended to establish novel links more than who either had only visited the removal plants or avoided to do so.

With the experimental manipulation of real networks, our study shows that despite their reorganizational ability, plant–pollinator networks changed towards a more fragile state when generalist plants are lost.

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:

Preface                                                                                                                        

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.

SCAPE gets a new website and registration for the 2020 conference is now open

SCAPE-logo_dark

The Scandinavian Association for Pollination Ecology (SCAPE) now has a dedicated website:  https://scape-pollination.org/

The site includes some history of the conference and links to old programmes and abstract booklets, and we will use this for all future conference announcements.  SCAPE2020 will be online and registration to give a talk or just attend is now open.  If you’re tweeting about it please use the hashtag #SCAPE2020

My thanks to Yannick Klomberg for developing and maintaining the website.

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.

Recent pollinator and pollination related research that’s caught my eye

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As I near completion of the copy-editing phase of my forthcoming book it’s frustrating to see all of the great research that’s been produced in recent weeks that I probably won’t be able to cite!  Here’s a few things that caught my eye:

Damon Hall and Dino Martins have a short piece on Human dimensions of insect pollinator conservation in Current Opinion in Insect Science.  My favourite line is: “any call to ‘save the bees’ must be a call to stabilize agriculture”.  Amen to that.

In the journal New Phytologist, Rhiannon Dalrymple and colleagues, including Angela Moles who hosted me during my recent stay in Australia, have a great study entitled Macroecological patterns in flower colour are shaped by both biotic and abiotic factors.  The title pretty much sums it up: in order to fully understand how flowers evolve we need to consider more than just their interactions with pollinators.  It’s another demonstration of how we must look beyond simplistic ideas about pollination syndromes to fully understand the complexities of the relationship between flowering plants and pollinators…..

…..talking of which, again in New Phytologist, Agnes Dellinger asks: Pollination syndromes in the 21st century: where do we stand and where may we go?  It’s an insightful and far-reaching review of a topic that has intrigued me for more than 25 years.  There are still a lot of questions that need to be asked about a conceptual framework that, up until the 1990s, most people in ecology and biology accepted rather uncritically.  One of the main unanswered questions for me is how further study of largely unexplored floras will reveal the existence of new pollination systems/syndromes.  Which leads nicely to….

…..an amazing paper in Nature this week by Rodrigo Cámara-Leret et al. showing that New Guinea has the world’s richest island flora.  The described flora includes 13,634 plant species, 68% of which are endemic to New Guinea!  And the description of new species each year is not leveling off, there’s still more to be discovered.  A commentary on the paper by Vojtech Novotny and Kenneth Molem sets some wider context to the work, and quite a number of media outlets have covered the story.  Why is this relevant to pollinators and pollination?  Well, we actually know very little about this critical aspect of the ecology of the island: there’s only a handful of published studies of plant-pollinator interactions from New Guinea, mostly focused on figs, bird-flower interactions, and a couple of crops.  For such a biodiverse part of the world that’s a big gap in our understanding.

Finally, James Reilly, Rachael Winfree and colleagues have a paper in Proceedings of the Royal Society series B showing that: Crop production in the USA is frequently limited by a lack of pollinators.  Most significant findings to me were that of the seven crops studied, five of them have their yields limited by lack of pollinators, and that even in areas of highly intensive farming, wild bees provided as much pollination service as honeybees.

That’s a few of the things that I spotted this week; what have you seen that’s excited or intrigued you?  Feel free to comment.