Due to the rapid decline in invertebrate species essential to food production, Professor Dave Goulson and activist Vicki Hird called on ORFC 2023 delegates to adopt practices that conserve beneficial insects and be ambassadors for insects in the broader community.
Finding solutions to the ‘insect apocalypse’ was the theme of the session chaired by Vicki Hird, Head of Agriculture and Supply Chains at Sustain, and Dave Goulson, Professor of Biology at the University of Sussex, which took place on day two of the Oxford Real Agriculture Conference 2023 took place.
Ms Hird began by stressing that while invertebrates are at the heart of our food system, their value is largely neglected in modern society. In fact, until now their importance has been judged by how much damage they cause, which has become the main focus of research, and how invertebrates are viewed, she pointed out.
However, with growing evidence from longitudinal studies, the broader community is beginning to see the issues posed by the large-scale decline of these small but powerful creatures, Ms Hird said.
She then introduced the session’s guest speaker, Dave Goulson, who is a leading invertebrate researcher specializing in bee ecology and the author of several books.
Prof. Goulson, often referred to as an “activist researcher,” has taken on the role of bridging the gap between researchers, activists and policymakers for the benefit of the insect world.
When asked by Ms Hird if an insect apocalypse was imminent, Prof Goulson confirmed that insect numbers are indeed declining. But he also emphasized that there are huge knowledge gaps in the world of insects and an estimated three to four million species are still waiting to be discovered.
He added that very few species of insects are counted, monitored and studied on a regular basis. However, with few exceptions, the majority appear to be in decline. To illustrate the seriousness of the problem, Prof. Goulson cited the following facts:
- Butterflies have been declining in abundance over the past 50 years
- The ranges of hoverflies and wild bees have declined by 30% since 1990
- According to reports, the biomass of flying insects in a German nature reserve has decreased by 76%
- Insects have been in decline for at least 80 years
- Global data analysis shows a 1-2% decline in insect species per year
Reminiscent of days gone by when car windows were covered with flying insects in the summer, Ms Hird noted that the decline in invertebrates is also having an impact on species that feed on them, such as bats and birds, as well as on plants and nature, who depend on them.
She then asked Prof. Goulson to share with the audience the main message of his Sunday Times bestseller, Silent Earth. The professor explained that insects make up a large part of our biodiversity, accounting for 70% of all species on earth, and essentially glue the entire ecosystem together by being pollinators, food for many animals, and important biocontrol and recycling agents, among other things.
“Our destiny is inseparable from that of insects, whether we like them or not,” he said. “And that’s why we need to change direction.”
Factors contributing to the insect apocalypse
Prof Goulson pointed out that insects are one of the oldest creatures on the planet, having existed for 480 million years and surviving five mass extinctions. However, a combination of man-made factors significantly affected their survival, including:
- intensification of agriculture
- use of pesticides
- habitat loss
- fertilizer
- light pollution
- invasive species
- Diseases
He explained that insects are remarkably adaptable creatures and could probably survive some of the above challenges. However, when faced with all of these factors at the same time, adaptability becomes almost impossible.
Ms Hird added that because of the large surface area-to-volume ratio of invertebrates, any sustained change in temperature and humidity will have an amplified impact on populations.
To steer the discussion towards solving the insect apocalypse, she asked how farmers and the general public can get involved and help invertebrates get back on their feet.
In response, Prof Goulson said that everyone can do their part to alleviate the crisis, regardless of who they are or what they do, because insects live all around us. Also, unlike many endangered animals, insects could make a quick recovery if “we just gave them a place to live and stopped poisoning them,” he added.
The professor stressed the importance of reducing insect exposure to pesticides, as this is one of the main reasons for the decline in species richness. He mentioned that the EU has already launched plans to halve the use of pesticides in the near future, while the UK continues to see an increase in the number of sprays applied per field.
In particular, the number of pesticide products in the UK has increased by 70% since 1990 and in particular the choice of sprays to treat OSR has tripled since 1988.
While integrated pest management (IPM) seems like the obvious choice when it comes to reducing pesticide use, there is unclear guidance on how farmers should integrate it into their systems, Prof Goulson said.
In addition, fertilizers also have a profound effect on insects and the environment in general, although they tend to be left out of the equation, the professor noted. He explained that nitrification of soils and rivers through the use of fertilizers has a significant impact on biodiversity as it exerts selective pressure on native species.
Produce food while protecting nature
Part of the long-term solution to the insect apocalypse is setting aside the least productive pieces of land to be reclaimed by wildlife and nature, Prof Goulson said. To show that farming with nature doesn’t have to mean sacrificing yields, he shared the results of a study carried out at the UK’s Center for Ecology and Hydrology in 2015.
Over a five-year period, researchers applied the following three treatments to a 1,000-acre farm that previously functioned as an intensive production system:
- Treatment 1: as usual
- Treatment 2: 3% Land converted to wildlife habitat
- Treatment 3: 8% of the land has been converted into wildlife habitats
Changes in crop production were monitored using yield maps and related to the regional average at the end of the study. Due to increases in pollination and other ecosystem services, the fields with wild streaks produced higher yields than the control fields after a three-year period, as shown in the graph below:
Changes in crop yield under different treatment conditions. The dashed line represents the regional average (Pywell et al, 2015)
Adding to the discussion, an audience member spoke of an ongoing study planting wildflower strips through the center of fields and along the edges, saying researchers had already seen significant increases in production.
Commenting on the above study, Prof. Goulson said: “If we can show that we can still produce plenty of food while taking better care of nature, then everyone wins.”
With land unsuitable for food production, there are options for rewilding, supporting biodiversity, capturing carbon and providing recreational tourism. He added that cultivating vast areas with a single crop not only affects soil health, but also disproportionately benefits a small number of insect species.
Echoing Prof Goulson’s words about the urgent need for change, Ms Hird said: “We need to act as citizens and listen to our politicians, local authorities and governments to do things differently and support growers and farmers to do the same do.”
Finally, Ms Hird highlighted the role the everyday gardener can play in supporting invertebrate species. Because landscape homogenization is a major factor in insect decline, she suggested leaving gardens a little messy to create additional insect habitats.
Citizen science programs and creating public engagement are also an important part of the picture, Prof Goulson said, and can often provide powerful data alongside educating the public.
In her closing remarks, Ms. Hird encouraged the audience to become bug ambassadors to friends and family and “get everyone to rebug” if they can.
