Written Evidence submitted by Buglife (INS0038)

The Invertebrate Conservation Trust

Summary

-          Insect populations are declining globally with estimates of around 40% of all species at risk of extinction.

-          Both the diversity and abundance of insects is in decline – data collected by the Bugs Matter survey suggests that the abundance of flying insects has fallen by 64% between 2004 and 2022.  Similar trends have been detected by scientific studies around the world.

-          Insects play a critical role in food security, pollinating crops, maintaining productive soils, and controlling pests.

-          The global loss of pollinators is thought to be causing around 500,000 early deaths a year due to reduced supplies of healthy foods.

-          Habitat loss and fragmentation, pollution, and Invasive Non-Native Species continue to cause insect declines - habitats must be restored, and these pressures reduced.

-          To reverse insect declines and improve food security it is essential to secure full participation across government to significantly increase resources available to drive change.

-          Policy to protect insects must be improved and updated to reflect the evidence of decline and understanding of the pressures they face. Effective solutions must be scaled up and embedded in environmental and agricultural legislation.

-          The England National Pollinator Action Strategy runs until 2024, it must be urgently updated in response to pollinator declines.

About Buglife

Buglife is the only organisation in Europe devoted to the conservation of all invertebrates. Our aim is to halt the extinction of invertebrate species and to achieve sustainable populations of invertebrates.

Introduction

Insects are the vital foundations of our ecosystems, playing key roles in, pollination, nutrient cycling, pest control, and as a food source for birds and other insectivores[1].

Food security is crucially dependent on the ecosystem services provided by insects. Insect pollination facilitates 7–8% of the total value of agricultural food production worldwide[2] and 70% of all crop species rely upon insect pollination[3]. A recent study found the global loss of pollinators to be causing around 500,000 early deaths a year due to reduced supplies of healthy foods[4]. Without insects such as dung beetles, nutrient recycling would cease, and soils degrade. While ladybirds, wasps, earwigs, and lacewings provide natural pest control by feeding on aphids and caterpillars that can overwhelm and destroy crops.

• The current evidence base for insect abundance in the UK, and the gaps in scientific understanding that require further research.

Most known species are invertebrates, with roughly one million named insects, and an estimated four million yet to be discovered[5]. Invertebrates are far less studied than vertebrate species, however, we have a reasonable idea of insect species distribution in the UK, especially for habitat specialists.

There is now an increasing body of evidence that indicates population declines in insects at global scales[6] [7] [8] [9] [10]. Current rates of decline could lead to the extinction of 41% of the world’s insect species over the next few decades, with butterflies, moths, bees, wasps, and dung beetles amongst the most at risk.

In the UK, most data on insect occurrence have been generated by individuals and takes the form of presence and absence distribution maps. As a result, status assessments have been based on changes in distribution. However, when assessing environmental health and food productivity the more important measure is the abundance of pollinating insects, changes in distribution usually underestimate changes in abundance, a species can decline very significantly in numbers in a locality before it disappears.

The Bugs Matter Citizen Science Survey[11] - led by conservation charities Kent Wildlife Trust and Buglife, is the only widespread flying insect abundance survey in the UK, found a 64% decline in insect numbers sampled on vehicle number plates between 2004 and 2022. The decline is 5% greater than that observed between 2004 and 2021, however, it is not clear what proportion of this decline is due to the long-term trend or the result of record summer temperatures. England, Northern Ireland, and Wales saw continued declines into 2022, but figures for Scotland showed an upward trend.

The national rate of change in flying insect abundance that may be inferred by this study, a decline of 35.4% per decade, is much higher than the longer term -6.6/decade rate of annual moth change calculated by[12] , however, the figures are similar to more recent trends, such as the change in insect numbers sampled on vehicle windscreens recorded on two transects in Denmark between 1997 and 2017, -38.0%/decade and -46.0%/decade[13], and are slightly higher than the -28.0% decadal change in the biomass of flying insects in malaise traps on nature reserves in Germany between 1990 and 2011[14].

The State of the UK’s Butterflies 2022 report shows that 80% of butterflies in the UK have declined since the 1970s. Species have, on average, decreased by more than a quarter (27% decrease) in abundance and lost over two-thirds (68% decrease) of their distribution since 1976.

In the last century, 20 bee and wasp species have gone extinct in Britain[15]. Two species of UK bumblebee became extinct and a third of the remaining species are listed on conservation priority species lists.

59% of invertebrate species included in the 2016 State of Nature Report are declining in distribution. Among the species included, 42% showed strong or moderate declines, 31% showed slight change, and 27% showed strong or moderate increases. 54% of species declined and 46% increased over the short term[16].

Bees and hoverflies form the basis of the UK Government’s Pollinating Insects metric which shows on average a 20% decline in distribution area for species between 1980 –and 2019, mostly driven by the contracting ranges of hoverflies[17].

Freshwater insects play a vital role in maintaining clean water; breaking down and filtering organic matter and providing a food source for fish, birds, and mammals. A major source of information on the global status of freshwater insects is the IUCN Red List. 34% of the 7,784 freshwater invertebrate species assessed are considered at risk of extinction. A further 32% are classed as Data Deficient – if only a small proportion are found to be threatened this could push the overall figure of at risk of extinction closer to 50%.

In the UK, the State of Nature Occupancy indicator trend data for 359 freshwater invertebrate species shows in the short term some 52% of species are in decline, while in the long term, 58% are in decline[18]. Mayflies and aquatic bugs are faring particularly badly with 54% and 53% declines.

Continued research and a greater evidence base are needed to better understand the complete picture of insect abundance, the full value of insects, and the requirements insects need to survive and recover. It is also important to consider the role of insects in light of the declines in other invertebrates that carry out similar ecosystem services. For example, a study of earthworm data in the UK shows the equivalent of 33% - 41% abundance declines over 25 years[19].

UK Research and Innovation should continue to secure funding streams for insect-focused research such as the Drivers and Repercussions of UK Insect Declines (DRUID) project[20]. A long-term funding programme should seek to address knowledge gaps and confidence in insect distribution and abundance, including supporting citizen science surveys, and surveys across all insect groups.

The UK Pollinator Monitoring Scheme (PoMS)[21] will go some way to improving our data and understanding, however, we will need a few more years’ worth of data before any analysis can be undertaken.

• The effects of pesticides, such as neonicotinoids or other agricultural control methods on insects including pollinators and their impact on UK food security.

The widespread use of neonicotinoid pesticides is a significant ongoing contributor to the reduction in insect abundance[22] [23] [24]. Neonicotinoid use has resulted in a reduction in the overwintering success of honeybee hives[25], significant declines in the distribution of 40% of wild bee species studied[26] and was implicated in butterfly population declines[27]. This resulted in reduced pollination services and crop yields[28]. Bee pollination is shown to provide greater economic returns than the use of pesticides with yield and gross margins greater in fields with higher pollinator abundance than in fields with reduced pollinator abundance[29]. Analysis also showed increased yields following the EU ban on neonicotinoids, with oilseed rape in the UK yielding on average 3.6 tonnes per hectare in the three years following the ban, compared to 3.4 in the five years prior to the ban[30].

For most pesticides, we do not know what risk they pose to pollinators in the environment as no science has been done.

Currently, the pre-approval tests that pesticides must pass only look at data on short-term effects on Honeybees. This does not protect Honeybees from long-term harm or sub-lethal effects and provides little or no protection for other pollinators - as Honeybees are a poor test surrogate for wild pollinators[31].

In 2010 the Government concluded that pre-approval tests for pesticides were inadequate to protect pollinators, but the UK has yet to introduce any new tests to help ensure that future pesticides are wild pollinator safe.

Different groups of insects are affected by pesticides in different ways, so a range of species must be included in the pre-approval testing process.

While the law says that pesticides that cause unacceptable harm to the environment must not be approved[32], if new chemicals are approved without adequate pollinator safety data, then a blind eye is being turned.

Risk assessments of pesticides must be independent and scientific, and the public must have the opportunity to participate in this important environmental decision-making.

Research shows co-formulants, in herbicides and other pesticides may contribute to global insect declines. For instance, some glyphosate-based herbicides can cause high levels of mortality to bumblebees, but it is not the active ingredient[33] that is harmful, but the other ingredients that are included in the pesticide product. Of particular concern are the alcohol ethoxylates which are now directly implicated in field-level impacts on bumblebee survival[34]. These coformulants are not subject to comparable safety testing.

Neonicotinoids can also damage freshwater ecosystem systems[35]. Mayflies, caddisflies, flies, and beetles suffer from lethal and sublethal effects of neonicotinoid exposure[36] [37]. There are three main pathways for neonicotinoids to enter the freshwater environment, firstly as a seed coating for field crops, approved through derogations, secondly as sprays for crops and domestic gardens, and thirdly as an externally applied arthropod parasite treatment for pets.

Veterinary Medicines

Veterinary medicines such as those used for both internal and external parasite control threaten soil-dwelling invertebrates and can lead to significant pollution of freshwaters. These include substances that are banned for routine agricultural use such as neonicotinoids.

Researchers have found widespread contamination of English rivers with neurotoxic pesticides commonly used in veterinary flea products: fipronil and the neonicotinoid imidacloprid[38]. The concentrations found often far exceeded accepted safe limits.

Insects such as dung beetles are especially sensitive to medicines used to treat parasitic worms[39]. Adult dung beetles are attracted to dung parasiticide residues this results in the abundance of adult and larval stages of dung beetles being significantly reduced in dung containing parasiticide residues. Dung Beetles fertilise and aerate soils and help control livestock parasite burdens on pastures. Dung Beetles also help to reduce greenhouse gas emissions from dung and the pasture ecosystem[40]. It has been estimated that dung beetles may save the UK cattle industry £367 million per annum through the provision of ecosystem services[41].

The use of veterinary medicines needs to be reduced and only used as part of a more sustainable suite of treatment and management options.

Increased monitoring of veterinary medicines needs to be introduced and include substantive responses to environmental risks. Improved environmental risk assessments must be introduced into the approval process for these potentially very harmful substances accounting for the impact of soil and freshwater biodiversity.

Further chemicals

Other chemicals including industrial pollutants and air pollutants can impact insect populations and must be considered. Heavy metals can be directly toxic to insects leading to death, reduced movement or reduced reproductive success[42] [43]. Emerging research on Per-and polyfluoroalkyl substances (PFAS) shows them to be widely used in insecticides[44] leading to contaminated soils and aquatic environments[45]. The impacts of PFAS on insects is not fully understood however studies suggest exposure can decrease reproductive success in bumblebees[46] and adversely affect activity, temperament, hive maintenance and defence in Western Honeybees (Apis mellifera) [47].

• The extent that biodiversity initiatives, such as creating reservoir populations, are addressing insect decline and whether there is sufficient co-ordination with the UK food system.

Many of our most threatened insects are only found in a small number of places. These places are often remnants of once widespread wildlife-rich habitats such as flower-rich grassland, ancient woodlands, dunes, heathlands, and wetlands. Yet agricultural intensification, and the pressure for new development, means that we are continuing to lose these irreplaceable wildlife refuges at an alarming rate.

The current suite of protected areas in the UK includes many sites that are important for insects; however, equally important areas receive no protection and continue to be damaged and destroyed by urbanisation, changing agricultural and land management practices, environmental pollution, invasive non-native species, and many other factors.

The most important places must be identified and recognised – given formal protection to prevent their loss or damage.

Buglife has identified the UK’s Important Invertebrate Areas[48] that must now be given protection from development and other land-use changes. Important Invertebrate Areas support nationally or globally important populations of species of conservation concern; exhibit exceptional species richness; are home to a particularly rare or restricted (e.g., highly specialised) invertebrate assemblage; or feature an exceptional example of a habitat of national or global importance to invertebrate conservation. Affording protection to Important Invertebrate Areas will help to address the decline in invertebrate species and could help the Government meet their 30x30 targets ensuring they are protected and managed increasing biodiversity while supporting UK food security.

The areas where insects thrive are not only being lost, but they are also highly fragmented. This reduces the amount of available habitat to support viable populations, and results in many species being unable to move through the landscape, colonise new areas or respond to threats such as climate change.

Buglife has mapped a nature recovery network of insect pathways across the UK required to reconnect and restore the best habitats for insects in a project called B-Lines[49]. The B-Lines mapping, funded in part by the Government, provides a network of 3km-wide pathways that will benefit all wildlife. When 10% of a B-Line is wildflower-rich habitat it starts to provide that essential connectivity that wildlife needs to thrive. This is the most cost-effective approach to restoring grassland biodiversity and engaging local communities in agricultural improvement, achieving the same benefit to dispersal without a targeted network approach would be five times as expensive[50].

B-Lines should be delivered through nationally led environmental and agricultural policy. The European Union has recently adopted B-Lines in the Revised EU Pollinator Initiative and is preparing the mapping of “Buzz-Lines” across Member States. The UK Government is yet to adopt B-Lines despite helping to fund the mapping work and the contribution B-Lines could make to meeting their environmental targets. Restoring and protecting wildflower-rich habitats within B-Lines would deliver connectivity of habitats essential for biodiversity to recover.

Flower-rich habitats help agriculture by supporting the pollinator populations that help grow crops, while also providing a home to the many wasps, beetles, flies, and other predators that help to control agricultural pests and improve soil health. Livestock grazed on flower-rich grasslands also have a more varied diet, making healthier animals and healthier food for people. The soil of flower-rich grasslands sequesters more carbon than species-poor grassland and can help combat climate change – some even capture more carbon than woodlands. B-Lines can also bring colour and wildlife closer to communities, by encouraging flowers across our towns and countryside improving health and wellbeing.

• Whether the threat to UK food security from insect decline receives sufficient cross-government priority.

Insect declines are significant and happening at pace, in many cases the rate of decline is increasing - therefore a significant increase in effort and coordination is required to avoid disruption to ecosystem functioning, and provision of ecosystem services – many of which underpin food security. Insect declines remain woefully under-prioritised across Government and existing initiatives are out of date and with limited progress on actions.

The 2013 England National Pollinator Strategy is no longer fit for purpose and will not deliver a reverse in the decline in pollinators. The strategy is outdated and fails to properly address many pressures pollinators face such as pesticides, light pollution and habitat connectivity and other issues covered in this written evidence. In contrast, the European Union has recently launched a revised Pollinator Initiative – ‘A New Deal for Pollinators’[51] updated to reflect new evidence and biodiversity commitments.

While the England National Pollinator Strategy includes guidelines, there are limited mechanisms to enforce the changes required to improve pollinator populations. The strategy should take a more comprehensive approach that considers the impacts of all pollinator species and the threats they face. The strategy, which only runs to 2024, remains under-resourced to ensure broad engagement, effective monitoring and deliver actions.

Information on the value of insect pollination to crop production is limited and must be better understood. Studies suggest the value to UK apple production may have previously been underestimated[52]. Insect pollination not only affects the quantity of production but can also have marked impacts on the quality of apples. Research indicates that due to the influence of pollination on both yield and quality in Gala variety of apples, there is potential for insect pollination services to improve UK output by up to £5.7 million per annum. The financial losses associated with pollinator decline show the loss of insects should be given greater consideration across government.

Cross-departmental work should be further encouraged to benefit insect populations and UK food security. While led by Defra, action to protect insects and food security should include policy within but not limited to the Department for Business and Trade, Science Innovation and Technology and The Department for Levelling Up, Housing and Communities. A revised National Pollinator Strategy would be a way to achieve this cross departmental approach.

• Additional policy initiatives and solutions needed in the UK and internationally to reduce and reverse the trends in insect decline.

Wild Pollinators and Honeybees

It is important that the focus on reversing insect declines extends beyond pollinators, and acknowledges issues associated with Honeybees[53]. There are estimated to be more than 4,000 species of insects in the UK that pollinate our crops and wild plants with growing recognition of the importance of wild pollinators such as flies, wasps, beetles, moths, and butterflies[54].

The Western Honeybee (Apis mellifera) provides highly valued pollination services for a range of agricultural crops, especially where there is a lack of wild pollinators, or where large numbers of bees are required to pollinate monocultures of mass flowering crops. At a ‘population’ level the numbers of hives are directly related to the number of beekeepers and the effort they put into sustaining their hives. Large colony size and honey stores also mean that domesticated honeybees are more robust to environmental shocks and pesticides when compared with bumblebees or solitary bees.

By concentrating attention on Honeybees there is a real risk that wild pollinators are forgotten, placing in jeopardy more effective and successful pollination of crops that require specialist pollinators[55]. Increasing the number of honeybees adds to the pressures on our suffering wild pollinators and potentially disrupts ecosystems[56]. Increased competition for flower resources can be measured up to 1,100m from a hive[57] and a single hive can consume the resources that would otherwise support 200,000 wild bees[58]. Honeybees can also transfer disease to wild bees, leading to community-level effects[59].

Non-pollinating insects must also be considered for their role in pest control and nutrient recycling. Insects can play a key role in controlling pest populations, many species are natural predators of pests, such as aphids and caterpillars. Insects play a crucial role in breaking down organic matter and returning nutrients into the soil, where they can be taken up by plants and other organisms.

Light pollution

Many plant species have evolved to rely on nocturnal pollinators because these pollinators are active at a time when other pollinators, are inactive. Previous research has almost exclusively focussed on diurnal insects, however, emerging evidence[60] shows nocturnal pollination to be particularly important to fruit plants such as strawberry[61] and bramble[62].

Nocturnal pollination continues to be overlooked and should be studied further to better understand predictions of crop pollination services[63] and its role in agriculture[64].

Light pollution reduces pollinator visits to flowers by 62% in some areas[65] and has been further implicated as a high-level driver of insect population decline[66]. One-third of insects attracted to streetlights and other fixed light sources will die as a consequence[67] and research has shown that street lighting can cause a 50% reduction in local moth abundance[68].

Research published in 2023 reveals a rapid increase in global light pollution levels by 10% every year for the past decade, representing a doubling of sky brightness every 8 years[69].

Existing UK laws and regulations relating to light pollution do not provide sufficient guidance and are not strong enough to tackle its increasing impact. The UK’s Environmental Protection Act 1990 (as amended) provides local authorities with statutory nuisance powers to address light pollution however, this has not resulted in a reduction in general light pollution. The threshold for light to be considered a statutory nuisance is high and only considers the impacts of artificial lighting on humans rather than the environment. This limits its application and is only applicable to a narrow area of impact.

Most lighting fixtures fall outside planning policy and there is insufficient knowledge in the sector to ensure guidance is followed. The National Planning Policy Framework offers little consideration for light pollution.

The last comprehensive consideration of light pollution by the Government was The Royal Commission on Environmental Pollution’s 2009 report - Artificial light in the environment, however, almost none of its recommendations have been implemented.

The Government has reneged on action on light pollution and has removed all mention of it from the Environmental Improvement Plan, despite the first version, published in 2018 including the commitment to “…ensure that noise and light pollution are managed effectively.”

The Government must recognise light as an active environmental pollutant by introducing a single driver to reduce light pollution and coordinate policy across government, including setting binding environmental targets to reduce existing levels and implement national monitoring of light pollution levels.

Air Pollution

Air pollutants such as nitrogen oxide and ozone may be contributing to insect declines by impacting health[70] and foraging activity[71]. Laboratory experiments show that diesel exhaust and ozone at levels lower than is considered safe under current air quality standards, significantly reduced insect pollinators including bees, flies, moths and butterflies by 62–70% and flower visits by 83–90%[72].

Invasive Non-Native Species

Invasive Non-Native Species (INNS) – plants, animals and other forms of life that establish themselves outside their natural range with negative effects – are a key cause of biodiversity loss and can cause extensive economic damage. Between 1960 and 2020 invasive alien species caused over US$1,130.6 billion (€1 trillion) in damage worldwide[73], with the annual cost of INNS to the British economy estimated to be £1.7 billion[74].

INNS have been shown to harm pollinators through increased competition, by disrupting interactions between species, affecting pollinators’ role in native plant communities and by vectoring diseases and pathogens[75]. The impact of Harlequin Ladybirds (Harmonia axyridis) on wildlife, has resulted in calls for stricter regulation of potentially invasive non-native insects as pest controls[76] and the growing use of insects as a novel food has raised concerns about lax biosecurity relating to insect farming[77]. Invasive plant species have also been shown to impact pollinators, out-competing native plants and changing native plant communities with subsequent knock-on effects[78].

There has been little progress on the importation and transportation of invasive species in soil or the biosecurity of insects in trade. Soil, including soil in potted plants, is a common pathway for invasive species into and around the UK. Many species are being and could be imported through this route that would be directly harmful to pollinators, but the inflow of agricultural pests through this route is an additional threat to pollinator populations as they create an added motivation for the widespread use of insecticides and other pesticides.

The importation of soils should be banned, and the internal movement of soil should be much more tightly controlled.

9 May 2023