Screening for pathogens

Our guest blog today comes from Luke Woodford, who recently completed a period working with Science and Advice for Scottish Agriculture.  His project looked at pathogens in bumblebee species and explored potential for a biology tool that would make screening easier and quicker.

Pollinating insects are essential for many crop and wildflower species across Scotland. But increasingly, the demand for pollination exceeds the capacity of local pollinating species¹, leading farmers to bring in commercially reared bees to supplement wild pollination. But what is the effect on native species, and do these new arrivals bring with them pathogens that could be damaging to local pollinators?

As part of the ‘Pollinator Strategy for Scotland’ – a 10-year plan aiming to improve pollinator health as well as our awareness and understanding of pollinators – I undertook a 3-month project at SASA (Science and Advice for Scottish Agriculture), developing a molecular biology tool to rapidly screen for some of the most common pathogens transmitted between bumblebee species.

Many farmers now import bumblebee nest boxes and place them in poly-tunnels to pollinate crops such as soft fruits. As a method of crop pollination, it’s rapid and efficient, but importing species into an ecosystem will always have an effect on existing inhabitants, especially fellow pollinators such as native bumblebees, hoverflies and butterflies. These species could be negatively affected by the sudden need to share resources, and the imported species could be carrying pathogens that may then spill over into the native pollinator population. Reports have shown that numbers of pollinating insects are decreasing at an alarming rate², so it is ever more important that we understand and monitor the spread of potentially harmful pathogens between wild and managed pollinators in local habitats.

To develop the screening tool, we first identified key bumblebee pathogens from the scientific literature, before design and optimisation work in the lab. Through repeated testing and refinement, a protocol was established that could determine if any of the key pathogens were present in a sample. With this sensitive and specific tool, SASA will now be able to quickly and cost-effectively screen selected samples from bumblebee boxes as part of their import inspection programme. The system can screen for Crithidia, Nosema, Apicystis and Locustacarus, all well-known bumblebee pathogens^3,4.

This tool will support the pollinator strategy by enabling SASA to quickly identify potential pathogens introduced with imported pollinators. In this way, we will be able to identify the source of such pathogens and aim to contain them before they can spread to native pollinators. SASA would also be able to report back to the suppliers of these imported bees and help them to improve the disease screening that they perform prior to shipment.

A further step in my work at SASA involved using a next generation DNA sequencing tool, the Oxford Nanopore MinION⁵, to screen bumblebees for unknown pathogens (shown connected to a PC in image above). We were aiming to detect any pathogens which aren’t routinely reported or known as pathogens of bumblebees, but which could be emerging threats. This work lays the foundation for SASA to develop screening for emerging diseases in pollinators. This would allow monitoring of low-level threats to native pollinators, which could prevent a major outbreak before it reaches a critical level, and identification of pathogens carried by bumblebees that may impact other parts of the ecosystem, such as crops.

Further reading:

1-https://www.sciencedirect.com/science/article/pii/S0960982209009828

2-https://www.sciencemag.org/news/2017/05/where-have-all-insects-gone

3-https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2664.12134

4- Colla S. R. et al (2006), Plight of the bumblebee pathogen spillover from commercial to wild populations. Biological conservation 129 (461-467) doi:10.1016/j.biocon.2005.11.013

5-https://www.technologyreview.com/s/607963/oxford-nanopores-hand-held-dna-analyzer-has-traveled-the-world/

Powering ahead for pollinators

Our guest blog today comes from Francis Williams, Environmental Project Manager at Scottish and Southern Electricity.  He reflects on a project in Thurso that with a few tweaks proved a real bonus for great yellow bumblebees (and other pollinators) in the north of Scotland.

Species rich grasslands are important habitats for pollinators

“Scottish and Southern Electricity Networks’ (SSEN) Caithness-Moray transmission link will play a key part in the country’s move to a low carbon economy, as it enables 1,200 megawatts of additional renewable capacity to connect to the electricity network in the north of Scotland.

The project is centred on a High Voltage Direct Current submarine cable in the Moray Firth, and in addition to the new cable, SSEN is also constructing new infrastructure and buildings to support the extra network capacity, including a new substation at Thurso.

The substation site is on land which had low plant diversity and limited ecological value. The surrounding area is dominated by improved farmland used for grazing with few areas of wildflower, and the only trees in the area were a strip of non-native conifers planted as shelter belt.

As a responsible developer, we are keen that our developments have a minimal impact on the local communities and environments that we operate. The planning permission required tree planting to screen the substation, a generic wild flower mix was specified in the initial planning submission too. During project development it was recognised that changes to the species mixes (both trees and wildflower mix) could present an opportunity to enhance local biodiversity.

Great Yellow Bumblebee, courtesy of SSE and (c) David Wood

After consulting the Bumblebee Conversation Trust local Conservation Officer, changes to the wild flower and tree species mix were identified that could create high quality habitat to benefit the Great Yellow Bumblebee, a rare endemic species found only in the North of Scotland. The measures introduced on site included;

• Hydro seeding of 10 hectares of flower-rich grassy meadows with different flowering plants such as bird’s-foot trefoil, red clover and knapweed
• Enhanced tree planting with native broadleaves including species which provide important early season nectar such as willow.
• A SUDS pond planted with marginal wetland vegetation to create a wider diversity of habitats.
• Small bare areas of ground and rock piles using reused material on south facing slopes to allow nesting and hibernation habitat.
• Ongoing contact with the Bumblebee Conservation Trust to allow for adaptive management if required.

After the platform substation was created, the screening bunds were formed and then dressed with top soil. Turves were retained where possible to try and retain some local seed.

In the summer of 2017 hydro seeding took place, using a local experienced contractor with tree planting following in winter of that year. The enhancements were monitored during installation by environmental staff.

The meadows have now enjoyed their first growing season and monthly inspections are being carried out to check on growth. Inspections have suggested that wild flowers are growing better on the less exposed south facing slopes. As the land is owned by SHE Transmission there is the opportunity to take a long term view.

The project intends to complement other conservation efforts in the area such as;

• The ‘Thurso: Gateway to the Great Yellow’ Bumblebee Conservation Trust project.
• The Highland and Caithness Biodiversity Action Plans (Great yellow bumblebee and other pollinators).
• The Pollinator Strategy for Scotland.

The project also aligned with the SSE sustainability strategy and our goal of working towards biodiversity net gain on our developments.”

Francis Williams, Environmental Project Manager SSEN

Making a b-line

Buglife’s B-lines is a UK-wide project designed to combat the loss of wildflowers and pollinators. By reducing habitat fragmentation and improving habitat connections the intention is to both restore high quality wildflower meadows whilst aiding species movement across Britain.

We recently attended workshops held in Glasgow, North Ayrshire and Edinburgh which tapped into local knowledge to both map existing beneficial habitats and identify where action could be taken to create links and habitat rich corridors.

Based on initial mapping and modelling the intention was that by inviting attendees from a range of agencies and community groups the maps would be as comprehensive as possible.

The work dovetails neatly with the Pollinator Strategy for Scotland, where habitat loss is identified amongst the chief threats facing pollinators.  If food, shelter and nesting sites can be increased then it follows that our pollinators will be better placed to thrive.

Knowing what pollinator friendly resources are out there is one key outcome of the B-Lines workshops, but arguably the highlighting of areas devoid of pollinator provision is equally important.

In the Edinburgh group some very encouraging signs emerged from the mapping exercise. The Lammermuir Hills across to the Pentland Hills soon emerged as a clear pollinator corridor. This was followed by suggestions that the natural opportunities offered by the River Esk corridors, the Water of Leith route and the Union Canal were areas we could focus on.  When we added parks and the John Muir Way along the shoreline we were moving into a comfortable position.

But that said there are still swathes of Edinburgh which need to see pollinator friendly resources created and managed. The mapping exercise clearly revealed ‘barren spots’ where effort is needed to address a lack of habitat.

We’ve lost 97% of wildflower-rich
meadows since the 1930’s

Given that we have lost 97% of our wildflower-rich grasslands since the 1930s it was perhaps inevitable that a less than satisfactory position would be the outcome of our survey.  We know too that 13 bee species have been lost to Britain in that same period and that the Great Yellow bumblebee has gone from 90% of its immediate post-war range. However, with the knowledge we gleaned from the Buglife workshop there is a better prospect of creating coherent and valuable pollinator corridors.

The drive will now be on to encourage the developments of an increased B-lines network and look for opportunities to restore and create new wildflower rich habitats. Planting more wildflower meadows will provide vital food sources and adding grasslands and perhaps hedgerows will increase potential nesting sites. Connectivity is the key and that race is on now to maximise what we have and create what we don’t.

Key steps that have been identified include:

• Planting more nectar and pollen-rich flowers, shrubs and trees
• Cutting grass less often
• Avoiding using pesticides and herbicides
• Leaving some ‘wild’ areas for shelter and nesting sites

Helping pollinators in this way will help people too. It is estimated that in the region of 75% of our food crops are pollinated by bees and other pollinators – that’s a figure that includes some of our most popular food stuffs such as apples, tomatoes, strawberries and raspberries. Add to the mix the free pollination services provided to our favourite parkland and garden plants and the value of pollinators is clear.

And that’s before we tally up the natural health service value of simply making us feel better and more inclined to enjoy the outdoors.

Helping our pollinators has never been more crucial. Knowing what we have, and what we need, is a major step on the route to improving the lot of our hard-pressed pollinators.

Buglife is working to expand its B-Line initiative across the Central Scotland Green Network area. With the support of SNH and EU Life funding through the ECoCo Life project the project aims to provide long-term solutions to the loss of both wildflowers and pollinators.

You can help – If you want your garden to be a valuable part of the jigsaw then there are many things you could plant in your space. Here’s a list of just a few pollinator friendly options – Ivy, willow, hawthorn, cherry, crocus, rec clover, bird’s-foot trefoil, scabious, knapweed, yarrow, yellow rattle, vipers bugloss, cornflower, cowslip, cosmos, sage, snowdrop, Echinops, catmint, foxglove, alium, globe arthichoke, thyme, apple, pear, heather, lungwort, rosemary and lavender.

Further reading

Buglife https://www.buglife.org.uk/b-lines-hub

Living wall … and that’s not all

Living walls are an innovative green infrastructure approach which uses vertical surfaces to allow plants to flourish where space is limited. They are being installed around the world to offset vegetation loss, enhance local biodiversity and connect people with nature in the cities and towns. Last week we had one installed at our Battleby office in Perthshire – as a demonstration site – and we invite everyone to visit.

Before and after images of Living Wall

The installation of a living wall at Battleby was a process which took place over two days with installation of the fabric and irrigation system on the first day and planting of the plants on the second day  – all 491 of them!

About the process
The building of the wall was suggested by Martin Faulker of our Green Infrastructure team. Keen to demonstrate how cities and towns can be greener, even where space is at a premium, he seized the opportunity to make a plea for a demonstration model as part of the Scottish Natural Heritage Staff Suggestion scheme.

The wall materials came from Scotscape who have been building living walls and other green infrastructure nationwide for the last 30 years. The living wall was built from a  Fytotextile system which is light-weight and flexible. The felt rooting layer is made from recycled textile waste. The three layer system comprises a waterproofing layer, a rooting layer and a breathable pocket layer to contain the plants. Each 1m2 panel has an integrated irrigation line to keep the plants hydrated automatically. The installation was supervised by Alex Patience, a Bristol-based landscape architect.

Staff at Battleby were invited to help with the planting and many jumped at the opportunity to get their hands dirty and introduce the plants to their new home. Before the wall was even completed we had our first pollinator visit in the form of a queen bumblebee, securing some of its last food before the long, cold hibernation months.

Pollinator friendly plants included in the mix

All the plants were sourced from local suppliers in Scotland to ensure they’re suitable for our environment and were chosen for their benefits to biodiversity, air purifying capabilities and aesthetics. Depending on the selection of plants, a multitude of benefits can be obtained.

       A living wall can help to:
             – provide food and shelter for biodiversity
             – improve air quality
             – provide positive benefits to individual health and well-being
             – reduce surface run off
             – insulate buildings

Living walls are of particular benefit in the urban environment where space is limited. Innovative green infrastructure like this can help transform the cities we live in and create an environment that we actively want to live, work and play in.

Planting of living wall by staff

We welcome you to visit Battleby living wall and watch as the plants change throughout the season. Why not head to our office next Spring and Summer when you can enjoy our wildflower meadow, pollinator trail and Living Wall – a triple delight.

By Alice Brawley, Graduate Placement, Pollinator Strategy for Scotland
– Creating a Buzz in Buildings