50 years of the Rothamsted Insect Survey brings global benefits to food security and ecological research in the 21st century
Anniversaries are often a time to look back. But after taking stock of the past, it can be just as important to look to the future.
2014 saw the fiftieth anniversary of the Rothamsted Insect Survey (RIS), which has collected and cataloged more than 30 million insects across the UK. It’s information that informs farmers of when pest species might hit their crops, what animal disease vectors are flying, and is used by ecologists searching for the patterns that underpin the structure of biological communities.
Yet after 50 years its work is far from done. Indeed, the data become more and more valuable over time. As a changing climate alters the distribution and abundance of marauding crop pests, continued monitoring of new and existing insect threats to economically important crops such as cereals is crucial. Many of the insects, principally migrating aphids, also carry viral diseases that further undermine food security in agriculture across the world.
“The Rothamsted Insect Survey has amassed an incredible wealth of data and is now widely regarded as the most comprehensive and continual database in the world on terrestrial invertebrates,” says former RIS Project Leader Dr Richard Harrington who retired in 2015 from Rothamsted Research, an institute that receives strategic funding from UK bioscience funders BBSRC.
Supporting the survey’s work into the 21st century, RIS is now funded as a BBSRC National Capability — an institute-based resource and repository of data intended to benefit UK scientists and the wider scientific community across the world.
Indeed, insect suction-traps of the RIS design are spreading across the world as other countries develop similar surveillance and warning mechanisms, opening opportunities for collaboration between growers and industry with entomologists interested in the fundamental mechanisms behind the spread of insect populations.
Yesterday
When legendary entomologists L.R. ‘Roy’ Taylor and C.G. ‘Johnny’ Johnson flicked the switch on the first insect suction-trap in continuous operation at Rothamsted on 29 April 1964, they probably had no idea that their project would still be going 50 years later: that day there was a US nuclear test in the Nevada desert, and the Beatles had three singles in the top five in America.
Elements of the work had begun just before the Second World War with the development of a different type of trap — the light-trap to capture moths — by their colleague at Rothamsted, the entomologist C.B. Williams. Twenty years later, and against the backdrop of an explosion of concern at the effect of pesticides on wildlife following the release of Rachel Carson’s book Silent Spring in 1962, the researchers proposed expanding and developing the trap network nationwide: a likely and immediate benefit could be the ability to warn farmers when pest infestations were unlikely, saving them from spraying chemicals and thus reducing insecticide use.
The scientists also realised that a trap network could help investigations on the population biology of insects, including those of importance to agriculture. Funding from BBSRC’s forerunner, the Agricultural Research Council, supported the development of the two trap networks across the UK: a series of 12.2m suction-traps to trap aphids and other flying insects, and light-traps to capture moths, which are good barometers of environmental quality.
Here, there and everywhere
The RIS now provides the most extensive standardised data for any terrestrial invertebrate groups anywhere in the world. It has contributed to studies on the drivers of biodiversity, insecticide resistance, ecological community structure, aphid morphology and climate change — all topics of relevance to research on agriculture and food security. (See a research timeline summary at the bottom of this article.)
From 2012 RIS has been funded as a BBSRC National Capability (approximately 60% of the £500,000 annual running costs), along with much needed support from the agricultural industry, especially the British Beet Research Organisation and AHDB Cereals & Oilseeds, as well as from Rothamsted’s Lawes Agricultural Trust. RIS data have also formed the basis of a wide range of specific research projects funded by BBSRC, NERC, Defra (Natural England), the EU and others.
The major target of the suction-traps seen in the picture above and video are aphids. A meta-analysis has reported average yield losses of 10% from feeding damage by aphids across a range of crops. If virus damage was considered, this figure would rise, but a 10% yield loss across the roughly 3.8 million hectares of cereals and oilseed rape grown in the UK would cost upwards of £300 million — a figure that could be much higher if damage from aphid-transmitted viruses was included.
According to the PUSSTATS database, approximately three million hectares of cereals are treated with insecticides (including seed treatments, active area sprayed) in the UK. This will cost millions of pounds, and every time growers and farmers can delay or reduce insecticide use, they save money and can be more competitive, as well as avoiding potential environmental problems, such as killing beneficial natural enemy insects, or encouraging insecticide resistance.
Come together
From volunteers to working with industry and government, RIS has been a story of collaboration. Gathering such a vast amount of data has led to some innovative ways to collect and catalogue the insect samples. Long before the term ‘citizen science’ was invented, the RIS recruited volunteer insect enthusiasts to identify species of moth from the light-trap network.
Harrington says there are now approximately 100 volunteers working on the RIS project (with five full-time employees) and there have been around 500 volunteers over RIS’ 50 years; some individuals have been contributing their services — for free — for more than 40 years. Nowadays such efforts to ‘crowdsource’ scientific data are popular and increasingly common, and the RIS was a very early and successful pioneer of the concept, recording and storing all insects from the suction traps.
“They are an invaluable resource for studies of, for example, the natural enemies of aphids such as ladybirds and lacewings, wasps, the mosquito vectors of West Nile virus, and the midge vectors of Bluetongue virus of sheep and cattle,” says Harrington.
RIS suction-trap data were used by researchers at The Pirbright Institute (then called the Institute for Animal Health), which also receives strategic funding from BBSRC, to study the dynamics of the Culicoides biting midge disease vectors using specimens from the suction-trap network. These midges carry bluetongue disease, a major pest of sheep and other ruminants across the world; outbreaks can cost hundred of millions of pounds of lost economic output, leading to mass animal culls and hardship for farmers and rural communities.
The moth light-trap network has also revealed much about declining biodiversity across much of Britain. The 2013 State of Britain’s Larger Moths report from Butterfly Conservation reported a 28% decline in the total abundance of moths in the 337 species that were caught in enough numbers to analyse from 1968–2007. Worryingly, more than a third of these species declined by a half, especially in the south of the country, whereas declines in the north of Britain were offset by local increases. Moths play important roles as plant pollinators and these declines will have knock-on effects on the birds and mammals that depend on them for food.
The success of the network has seen elements of it spread around the world, in particular the suction-traps of the Rothamsted design have made it as far as China, New Zealand and South Africa. The RIS is therefore looking to expand on the EU funding in the past, which led to a common insect survey database and several joint publications. The UK Government through FERA and the agricultural industry have developed complementary systems.
“We will seek EU and other international funding for further international collaboration,” says Harrington. “It will involve much more work below the species level in the future and an increasing molecular component.”
This includes, for example, recognising cryptic species or subspecies which may vary in their pathogenicity to crops. The RIS team also hopes to monitor and identify the presence of plant- and insect-killing viruses in invasive species, and assess and predict changes in genetic characteristics in aphids in relation to changing environmental and agronomic factors.
“We also believe that we have the capability to chart trends in a range of pollinators, which could support those looking at whether and why pollination services are reducing,” says Harrington.
The proposed work on pollinators would complement and feed into other past and future BBSRC projects investigating the role and importance of pollinating insects in ensuring food security, and other ecosystem services.
Click here for more links to RIS research impacts. You can also follow the RIS on Twitter.
TIMELINE
• Official start of the Rothamsted Insect Survey (RIS) on 29 April, 1964, when the first suction-trap begins operating at Rothamsted
• By 1968, 60 moth traps are in place throughout the UK
• 1970s: Suction-traps of the Rothamsted design deployed by entomologists in other countries, first France in 1978
• 1976 sees the peak number of light-traps: 155 (now 84)
• 1977: highest number of moths in a single year — 629,868
• 1979 sees the peak number of suction-traps: 24 (now 15)
• The highest number of aphids caught in a year was 1,082,509 in 1979
• In the 1980s travel funds enable researchers across Europe to meet and form the informal EURAPHID group to share and utilise data and methodologies
• After the Fifth International Symposium on Aphids held in 1997, Spain, a workshop on suction-trapping is held in 1998. These events reinvigorate international collaboration
• 2000–2003 The EU-funded EXAMINE (EXploitation of Aphid Monitoring IN Europe) project establishes a common database for deposition and retrieval of data from the now Europe-wide suction-trap network
• 2000s: many papers published on the impacts of climate, land-use and pollution on the dynamics of aphids, moths and other insects
• After an outbreak in 2008 of bluetongue, a deadly disease of sheep and cattle, RIS researchers work with scientists from The Pirbright Institute to study the dynamics of the disease vectors, Culicoides biting midges, using specimens from the suction-trap network
• From 2012 RIS is funded as a BBSRC National Capability
• 2013: Delegates from 12 countries including China, South Africa and New Zealand attend a meeting of the Nordic Association of Agricultural Scientists in Sweden to provide an update on suction-trapping around the world and discuss more potential collaboration
• From 2013 a new database (known as ‘Paul’) is recommended as a databank and as a means to facilitate collaborative analyses. All Rothamsted and EXAMINE data from the suction-trap and light-trap networks are uploaded and further functionalities developed throughout 2014
