INNOVATION FOR IMPROVED STRAWBERRY POLLINATION BY COMMERCIAL BUMBLEBEES USING CAFFEINE

Lead Research Organisation: University of Greenwich
Department Name: Natural Resources Institute, FES

Abstract

Efficient pollination by insects, especially bees, is critical to ensuring food security and yields of many crops. Production of soft fruit such as strawberries in the UK is worth around £360m annually, is growing year on year but depends heavily upon pollination by insects, particularly bees. When pollination is inadequate it frequently results in misshapen fruit. Owing to inadequate numbers of wild pollinators in agricultural ecosystems, strawberry growers rely heavily on commercially-bought colonies of bumblebees to try to improve pollination, but this is not always sufficient. Misshapen fruit must still be harvested despite poor sales potential in order to control pest insects that otherwise build up on them, so under-pollination causes a significant unwanted cost to growers.

Successful fruit production requires bees to carry pollen between flowers of the same crop species. Foraging bees often specialise on one species, which helps ensure this pollen transfer. Plants encourage this by providing distinctive cues such as unique flower odours, colours or shape which bees remember. Low doses of caffeine make bees remember cues such as floral odour more accurately, and increase bees' foraging activity. This project will investigate whether it is possible to prime managed bumblebees on strawberry farms to prefer foraging on the flowers of the crop, in order to pollinate them more effectively.

The project will carry out experiments to test the ability of caffeine to improve crop pollination in field and laboratory settings. Bumblebees will be provided experimentally with caffeinated nectar alongside a synthetic strawberry flower's scent. Since caffeine improves bees' memory for the scents of flowers, the project will test whether these bees show increased foraging activity and attraction to strawberry flowers when they receive this priming treatment. We predict that if the preference of commercial bumblebees for strawberries is improved, the bees will visit more floers, be more efficient at pollinating the crop and thus will enable the production of higher-quality, more valuable fruit.

Field tests of this technology will be performed on working farms using bumblebees to pollinate their strawberry crop, measuring fruit quality and yield resulting from this bumblebee-priming technology. The outdoor trials will also be supported by laboratory and semi-field experiments that optimise this system to get the best dose and timing of the priming system. A final economic assessment in consultation with the projects collaborative private sector stakeholders who have invested in this research will consider the potential financial benefits to the farmer of using caffeine-primed bees.

We anticipate that evidence for enhanced pollination services delivered by bumblebees will provide a compelling commercial opportunity that adds value to bee colony provision and could ultimately lead to enhanced pollination and fruit set in other pollinator dependent crop species.

Technical Summary

Declining wild pollinator populations and increasing demand for soft fruit, year-round, means farmers increasingly rely on commercial or managed pollination services. Bumblebees in particular are excellent soft fruit pollinators, but there is scope to improve their efficiency and effectiveness, resulting in increased yield and fruit quality. There are also concerns about the impact of commercial bumblebees on wild bees, via competition for wildflower forage or vectoring of pathogens to the wild bees. Strengthening memory associations in Bombus terrestris for floral odours in strawberry crops would increase specificity and fidelity of bumblebees for the crop; this is expected to improve fruit yield and quality, as well as reducing interactions between wild and managed bees.

Headspace analysis will identify the composition of strawberry floral odour. We will create a synthetic odour blend to use in training. Consumption of caffeine strengthens bees' memory associations for odour in the lab; exposure to odours in the nest increases bees' preferences for the same odours outside the nest. Thus, we will test the potential of caffeine to improve bumblebee crop-specificity. We will use conditioning paradigms to train bees to associate crop-specific odours with a reward via provision of sugar solution containing floral odours in the nest, with and without caffeine added to the training solution. This will permit comparison of the preference for strawberry flowers and overall foraging activity and efficacy in the laboratory and the field. Detailed recording will be made of foraging preferences, activity levels before and after caffeine application and persistence of behaviours. On working farms, bee visits to strawberry flowers in polytunnels will be monitored, data on fruit set collated and floral constancy and pollen collection efficiency evaluated by analysis of pollen. An economic evaluation will establish the possible income benefits to farmers of this system.

Planned Impact

Demonstrating the possibility of improving crop pollination by modifying pollinator experiences in the nest, via compounds in their food, has implications for agriculture and horticulture in the UK and internationally. Specifically our work will impact:

1. Growers and grower bodies. Farmers producing glasshouse and polytunnel crops using managed pollinators to deliver pollination services to crops will benefit by improved efficiency of commercial bee colonies, resulting in a larger percentage of Class I fruit, fewer misshapen fruit, less wastage and reduced disposal costs of unsaleable product. It is anticipated that this will represent a significant commercial advantage to UK growers. The innovation may also help to ameliorate problems experienced when pollinator effort decreases in high temperature and humidity conditions in polytunnels, by increasing pollinator foraging focus and activity using caffeine. The industry-led nature of this project, responding to the needs of a grower organisation (Berry Gardens), and direct collaboration with growers themselves will permit us to work in a participatory way with growers to maximise communication with results and facilitate eventual takeup of positive findings.

2. Global horticulture. The outcomes could provide a system of pollinator enhancement relevant to a wide variety of horticultural crops globally including citrus and almonds - both multi-billion dollar industries in the US that rely on managed pollinators. The outcomes will have wider implications since plant chemicals in nectar are found across many genera of plants, and understanding their effects on bees more widely will allow risk assessments of large monocultures on bee health and better understanding of factors that contribute to bee decline (Vanbergen et al. 2013).

3. Commercial bumblebee producers. This innovation aligns with existing strategies to make commercial bumblebees more effective for growers, e.g. Biobest's Turbo hives, and may permit refinement of other emergent technologies such as bee-vectored entomopathogen biocontrols. This provides an opportunity for bumblebee producers to take bumblebee production to the next level of technology. It also enables mitigation of some environmental impacts of commercial bumblebee production by reducing interaction between wild and managed bumblebees and thus potential disease transmission and competition for wild resources.

4. Beekeepers. The project will provide information about the impacts of plant compounds on bees and pollinators generally. Understanding measures that could increase bee foraging effectiveness may be of interest to bee enthusiasts more widely.

5. Schools and local interest groups. Our work will help grow the public's broader understanding of the diversity of life, the importance of pollinators and agricultural ecosystems and will be of particular benefit to conflicting agendas such as agricultural production and conservation biology which often have opposing goals. Pitting food production against conservation of biological diversity are both concerned with managing natural resources based on societal mandates: agriculture focuses on the production of foods, whereas the focus of conservation is on the maintenance of biodiversity. The rational response is to consider both challenges together, as explained by Cook & Varsheny (2010).

6. Policymakers. Demonstration of ways to improve performance of commercial bumblebees to enhance soft fruit product yield and quality will impact agricultural policy in UK and internationally and the scope to improve yield and quality through enhancing pollination rather than yet more chemical inputs will broaden the agro-ecological intensification debate.

Publications

10 25 50
 
Description We have established that Bumble bee behaviour can be improved towards more effective pollination services through priming commercial bees with a caffeinated feed associated with odour of strawberries.
Exploitation Route Development of technologies that enhance bee behaviour in soft fruit farming maximising pollination services.
Sectors Agriculture, Food and Drink,Environment

URL https://www.nri.org/latest/news/2016/new-projects-at-nri-better-berries-with-bees-plus-improved-value-chains
 
Description Pollinator Advisory Steering Group - Defra
Geographic Reach Europe 
Policy Influence Type Participation in a advisory committee
Impact Changes to land management and influencing implementation of UK gov ies to address land use change.
 
Description Darwin Inititative
Amount £290,000 (GBP)
Funding ID 21-012 
Organisation Government of the UK 
Department Department for International Development (DfID)
Sector Public
Country United Kingdom
Start 04/2015 
End 03/2018
 
Description INNOVATION FOR IMPROVED STRAWBERRY POLLINATION BY COMMERCIAL BUMBLEBEES USING CAFFEINE
Amount £224,560 (GBP)
Funding ID BB/P007589/1 
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom
Start 05/2017 
End 04/2019
 
Description Harmful or healthy? Studying the effects of plant chemicals in nectar and pollen on bees 
Organisation Royal Botanic Gardens, Kew
Country United Kingdom 
Sector Charity/Non Profit 
PI Contribution Co authored proposal to Peter Sowerby Foundation
Collaborator Contribution Co authored proposal to Peter Sowerby Foundation
Impact None
Start Year 2018
 
Description Improved soft fruit pollination by bumblebees with caffeine BB/P007589/1 IPA Grant Awarded December 2016 Starts April 1st 2017 
Organisation National Institute of Agronomy and Botany (NIAB)
Country United Kingdom 
Sector Academic/University 
PI Contribution PI with Natural Resources Institute University of Greenwich. Leading on laboratory behaviour assessment of the role of caffeine in the behaviour of commercial bumblebees
Collaborator Contribution Co-I (co authors and research collaborators). Undertaking field based work evaluating nest box adaptations on bees infield.
Impact None yet from the specific collaboration around improving pollination in strawberry but these are in preparation for submission.
Start Year 2017
 
Description Improved soft fruit pollination by bumblebees with caffeine BB/P007589/1 IPA Grant Awarded December 2016 Starts April 1st 2017 
Organisation University of Greenwich
Department Department of Pharmaceutical, Chemical & Environmental Sciences
Country United Kingdom 
Sector Academic/University 
PI Contribution PI with Natural Resources Institute University of Greenwich. Leading on laboratory behaviour assessment of the role of caffeine in the behaviour of commercial bumblebees
Collaborator Contribution Co-I (co authors and research collaborators). Undertaking field based work evaluating nest box adaptations on bees infield.
Impact None yet from the specific collaboration around improving pollination in strawberry but these are in preparation for submission.
Start Year 2017
 
Description KEEP+ with Olombria Ltd. 
Organisation National Institute of Agronomy and Botany (NIAB)
Country United Kingdom 
Sector Academic/University 
PI Contribution Joint successful application to KEEP+ scheme for research funding to collect data around precision pollination systems for fruit crops. We were approached for this partnership in part because of previous successful experience via the BBSRC IPA award around caffeine and bumblebees, showing experience in precision pollination of soft fruit using managed pollinators. NRI team provided training, lab space, technical supervision and ongoing support to a graduate research assistant collecting data on this project.
Collaborator Contribution Support of NIAB EMR enabled field elements of this project to go ahead, use of field sites, expertise and use of polytunnels. Olombria Ltd. provided direct co-funding to the project.
Impact One graduate receiving training in precision pollination technology and chemical ecology, has gone on to pollination related PhD in Australia
Start Year 2019
 
Description The macronutrient regulation of adult worker honeybees 
Organisation Newcastle University
Department Institute of Neuroscience
Country United Kingdom 
Sector Academic/University 
PI Contribution Co-PI investigating the key nutritional components in honeybee diets for the development of a food supplement for commercial bees. Natural Products chemistry of pollen and nectar. The Jodrell Laboratory has world-class expertise in the characterization of phytochemicals from plants and is equipped with state-of-the-art LC-MS and GC-MS equipment, including NMR facilities that will all be used in Kew's contribution to this action. We have also undertaken a pollen sterol survey to establish the variation across plant taxa and inform how this might drive specialisation in bees for pollen.
Collaborator Contribution My partner on this collaboration is Prof GA Wright formerly of Newcastle now at Oxford who is the PI of the BBSRC funded parent project BB/P005276/1 The macronutrient regulation of adult worker honeybees. Her lab has been conducting the bioassays and preparing samples for sterol chemical analysis.
Impact Several outputs directly resulting from this action are in prep for publication. Other research outputs include Stevenson P.C. 2019. For antagonists and mutualists: the paradox of insect toxic secondary metabolites in nectar and pollen. Phytochemistry Reviews https://doi.org/10.1007/s11101-019-09642-y (in press) Davis, J.K, Aguirre, L.A., Barber, N.A, Stevenson, P.C. and Adler, L.S., From plant fungi to bee parasites: mycorrhizae and soil nutrients shape floral chemistry and bee pathogens. Ecology 100, e 02802 Egan, P., Adler, L.S., Irwin, R.E., Farrel, I.W., Palmer-young, E., Stevenson P.C. 2018. Crop Domestication Alters Floral Reward Chemistry with Potential Consequences for Pollinator Health Frontiers in Plant Science. 9, 1357 Outcomes include a further grant in review "The influence of diet on the honeybee lipidome" BB/T014210/1 Multidisciplinary combining anlaytical chemistry and insect nutritional studies
Start Year 2017
 
Title Flower visiting recording and analysis software 
Description A small software app for tablet or laptop permitting control of an array of robotic flowers for recording bee visitation. The software collates and displays the visit data to assist with researcher analysis. 
Type Of Technology Software 
Year Produced 2019 
Impact Still developing but potential to support PhD students' research and future projects. Potential to share to other labs subject to JHD agreement. 
 
Description Appearance on BBC All Over The Place CBBC TV 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Schools
Results and Impact Participated in a programme for CBBC and talked about Kew's and NRIs work on pollinators and bee diversity.
Year(s) Of Engagement Activity 2019
 
Description Bees Needs Week outreach event in Carnaby Street with Defra 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Supporters
Results and Impact Outreach activity for Defras bees needs week showcasing UKRI funded work on nectar and pollen chemistry and pollaintor health.
Year(s) Of Engagement Activity 2018
 
Description European Research Night at Natural History Museum 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Controbution to NHM european research night talking about UKRI funded work on nectar chemistry and pollaintor health.
Year(s) Of Engagement Activity 2018
 
Description HRH Prince CHarles patron of Kew visit and engagement. 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact I met with Prince Charles to discuss Kew's work on pollinators and discuss rewilding schemes and the importance of pollinator diversity for food security covering all UKRI projects.
Year(s) Of Engagement Activity 2019
 
Description Invited lecture to IUmperial College London 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Talk to Imperial College London (Silwood Park)
Year(s) Of Engagement Activity 2020
 
Description Invited talk: Royal Entomological Society Postgraduate Forum 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Around 35 postgraduate students from across the UK attended the meeting, which was about sharing experiences and science. Dr Arnold was one of the keynote speakers and the talk reflected on issues and opportunities around the current areas of research taking place. There was plenty of informal discussion and networking over the following day related to some of the key issues and potential new research directions.
Year(s) Of Engagement Activity 2020
 
Description Kew Science Festival 2019 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Kew science festival using various engagement tools to inform the public about the project and the conservation of pollinators for food security.
Year(s) Of Engagement Activity 2019
URL https://www.kew.org/about-us/press-media/kew-science-festival-returns-for-2019
 
Description Kew Science festival 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Open day with display of pollinator oriented research and activities from Kew Gardens to draw attention to the challenges facing pollinators and the research being undertaken by Kew to address pollinator declines. Also drawing attention to pollaintor diversity
Year(s) Of Engagement Activity 2018
URL https://www.kew.org/about-our-organisation/press-media/press-releases/press-release-kew-science-fest...
 
Description New Scientist Live with RES 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact A general outreach event around science; Dr Arnold volunteered at the Royal Entomological Society stall in her capacity as committee member and also representing the research organisation. The stall sought to engage people in aspects of insects, including beneficial insects, insect diversity, pollinator, and Hymenoptera. Dr Arnold had discussions with many children and their parents over the ~8 hour event and the stall was busy throughout the day.
Year(s) Of Engagement Activity 2018
URL https://live.newscientist.com/2018-official-show-guide#/
 
Description Pollinator Outreach Day 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Supporters
Results and Impact Open day with display of pollinator oriented research and activities in collaboration with Reading University to draw attention to the challenges facing pollinators and the research being undertaken by Kew and Reading to address pollinator declines.
Year(s) Of Engagement Activity 2016
 
Description Pollinator Outreach Day 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Open day with display of pollinator oriented research and activities in collaboration with Reading University to draw attention to the challenges facing pollinators and the research being undertaken by Kew and Reading to address pollinator declines.
Year(s) Of Engagement Activity 2017
URL https://www.youtube.com/watch?v=7HM4dQuaMSs
 
Description Royal Society Panel debate about Science Matters 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Formal debat with Professor Brian Cox host and the Royal Society infront of >1000 paying guests in Manchetser to debate the issues around food production and the impoortance of ecosystems services.
Year(s) Of Engagement Activity 2016
URL https://royalsociety.org/science-events-and-lectures/2016/12/science-matters-feeding-the-future/
 
Description Talk To Autralian National Radio 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact INterview wqith Professor Tim Entwistle for national public radio in Australia about Kew work on polliantors and the Hive.
Year(s) Of Engagement Activity 2017
 
Description Talk at Maidstone Horticultural Society 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Invited talk to a group of horticultural enthusiasts affiliated with RHS. Despite twin challenges of COVID-19 and appalling weather, around 30 people from a range of ages came to the talk, which covered general pollination issues but also presented the research carried out by project team on UKRI projects.
Year(s) Of Engagement Activity 2020
URL http://www.maidstonehorticulturalsociety.org/programme/
 
Description Talk at Medway BreatheEasy local group 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Around 20-25 members of a local community group attended a talk by Dr Arnold about pollinators and pollination, which included discussion of the project and its role in food security and benefits. Attendees reported that their interest in pollination was low before the talk but afterwards they were fascinated by the topic and there was a great deal of informal discussion afterwards.
Year(s) Of Engagement Activity 2019
URL https://twitter.com/sejarnold/status/1136202475877404673
 
Description Talk at Newington WI 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact A talk for Newington Women's Institute, a local group, on pollination generally but with reference to the BBSRC IPA project. Around 15 members of the group attended and there was lively debate and discussion afterwards. Several members reported they would be considering how they managed habitats for pollinators as a result, and were also curious about the project.
Year(s) Of Engagement Activity 2019