Written evidence submitted by Lancashire Wildlife Trust (INS0031)
I work for Lancashire Wildlife Trust as an Invertebrate Projects Officer, on behalf of whom I am responding to regarding the Call for Evidence – insect decline and UK food security (I am also the aculeate Hymenoptera verifier for Local Record Centres in Merseyside and Lancashire and the biological data resource site i-Record and am a member of the Bees, Wasps and Ants Recording Society - BWARS) and have seen both first hand – and through data analysis – the changes in populations of insects over the last decades both nationally and (especially) in the north west area where I undertake most work.
In terms of aculeate Hymenoptera (bees, wasps and ants), there have been great declines in abundance and/or distribution amongst this whole sub clade of insects – ranging from bumblebees to solitary bees, social and solitary wasps and ants. Likewise, some parasitic wasps – important as bio-control mechanisms in natural ecosystems – have much declined, though data on these is much less robust. From data analysis the greatest impact on Hymenoptera has been on those species that are specialist (relying on specific plants and/or habitats) or those most demanding in terms of habitat quality and quantity.
In the case of “demanding” bees it is the bumblebees (Bombus) which place most demands on the landscape in terms of a complex and long-lived life cycle - needing areas to nest (often long, tussocky grass), forage (plants – including willows and dandelions as vital sources, alongside the much declined “hay meadow” species) and overwintering sites (the latter often similar in nature to nesting areas). Of the UK fauna – at a national level - 2 species have become completely extinct in the last 100 years (with 1 unsuccessful re-introduction project – Bombus subterraneus) and others have vastly reduced their range and distribution. In the northwest alone, at least three species (Bombus humilis, Bombus distinguendus, Bombus sylvarum) have become almost certainly extinct in the last 100 years.
These species are typically associated with large areas of flower-rich grassland and are particularly susceptible to more intensive farming practices (that for the most part have contributed to around 97% loss of species rich grasslands over the last 100 years). In addition, species such as Bombus muscorum (which like the former 3 species is reliant on flower-rich grassland) has become vanishingly rare in Lancashire (with only 1 record in the past 100 years). An upland species – Bombus monticola – has become much less common in the northwest over the past 100 years, as moorland and heath-rich habitats have been continually drained, degraded, fragmented and afforested on a large scale.
Solitary species of bee such as Andrena tarsata (a small bee associated with Upright Tormentil and other Potentilla) is subject to a JNCC Species Action Recovery Plan and has declined dramatically in Lancashire (where virtually all lowland populations have become extinct). This mirrors the situation in Cornwall (pers. comm. with Cornwall based Hymenopterists and ecologists). There are at least two other solitary bees and a wasp (Vespula austriaca) that have become regionally extinct – and much declined nationally – in the past 50 years.
More generally there have been declines in abundance of bees, butterflies and hoverflies which is in part – almost certainly – due to climate change, in combination (certainly) with habitat loss and (equally and crucially) fragmentation – the latter allied to deterioration and degradation of soils and heavy uses of pesticides and fertilisers.
A big concern is the alignment and link between bees, wasps, butterflies and hoverflies (plus other “pollinators”) and the need for food security – creating an economically based class of insects and the expectation of plant associated insects to help provide food security, if we are to assume their importance (which we should). First and foremost, many important pollinators are extremely good “bioindicators” – the presence and abundance of most species is intrinsically linked with “healthy ecosystems”, which can only be achieved by the large-scale creation, restoration and re-connection of degraded and fragmented habitats.
As a first step, we desperately need better soils in the farmed landscape and in combination, a vast reduction (ideally complete cessation) in the use of inorganic fertilisers, pesticides and intensive grassland management including frequent ploughing (plus adoption of plough-free methods of soil / crop cultivation).
It would be great folly to expect kept Honey-bees / Hive Bees (Apis mellifera) to provide food security. There has been a great decline in the regulation and animal husbandry relating to Apiculture over the past 100 years and a probable increase, with hive numbers likely to be at their highest point since the late 1950’s (Ollerton, 2021).
This is hard to quantify / qualify v. accurately as there has been little formal data collection on hive numbers since the late 1970’s (the last official UK submission of data was in 1977, since when data has been unofficial – Ollerton, 2021). This has come at a time when there has a resurgence in the interest in beekeeping as a “hobby” (rather than as a truly commercial enterprise), sometimes with the very worrying mis-conception that Honey-bees are in “danger and decline”. Honey-bees are already a “card carrying economic insect” but they are far from being a useful bio-indicator, as an essentially farmed and nurtured animal. Honey-bees can and are used for targeted crop pollination (Oil-seed Rape, orchards etc.), but they obviously need to be sustained when their “target crop” is not in flower, so place a great demand on the landscape in terms of floral resources and are also in direct competition with wild pollinators for a finite, much diminished resource. To an extent this could be mitigated if there was a requirement for beekeepers to create habitat, but they are possibly the most striking example of a “farmed” animal where the provision of food - in the form of flowers – need not be provided by the farmer (the apiarist / beekeeper – though beekeepers routinely supplement hives with large blocks of sugar-based “fondant” which obviously provides no benefit in terms of pollination).
There is common ground when it comes to Honeybees and wild bees / other pollinators when it comes to habitat loss and heavy use of pestidices and fertilisers /– toxicity to insects and a replacement of species (flower)-rich grassland with monocultures of crops and grass dominated pastures which provide no “food for pollinators”.
Ultimately, the biggest proven threats to insect abundance and diversity are a reduction in “condition” or “quality” of habitats, complete loss of habitats and fragmentation of all habitats, with climate change / variance almost certainly having a negative effect on many species. Somewhat perversely, diversity of aculeate Hymenoptera in the UK is slightly higher than it was historically (when much of the serious decline of certain bee species occurred), but this is certainly attributable to species with a restricted southern UK (or mainland Europe) distribution expanding their ranges / crossing the channel. The latter would seem almost certainly to be triggered by environmental / climactic change.
Most worryingly, it seems that “connectivity” (of habitats – i.e., lack of fragmentation) has been removed from the latest version of the Biodiversity Net Gain Matrix. Connectivity – and strengthening “ecological networks” and corridors - will underpin the ability of our native insect fauna to survive, move and thrive (helping to reduce the very negative effects of habitat fragmentation, isolation of populations and lack of a means for populations to disperse effectively and sustainably).
In summary to the main questions:
• The current evidence base for insect abundance in the UK, and the gaps in scientific understanding that require further research = Yes
• The effects of pesticides, such as neonicotinoids or other agricultural control methods on insects including pollinators and their impact on UK food security; = Strong evidence of negative effects and ideally this would lead to a complete ban on neonicotinoids using the precautionary priniciple that is vital in conservation of biodiversity. At the very least, “neonics” are harmful to insects in small doses and the only non-detrimental effect on pollinators would be to look at alternative methods of pest control. The most obvious, natural solution to this would be to have natural bio-control of ecosystems / food crops e.g. midges, lacewing larvae, hoverfly larvae, ladybirds, aphid-hunting solitary wasps (aculeate Hymenoptera) and parasitoid wasps (Ichneumonoidea as well as other sub families of parasitic wasps) and their controlling effect on insect pests of food crops. This need not be achieved by rearing and release of these important insects but could equally achieved through creation, restoration and management of their habitats - which are rather modest in many cases (long / tussocky grass, water features, hedgerows, scrub and an increase in habitat mosaics – plus better soils for ground hunting beetles e.g. rove beetles – in essence; very achievable, low maintenance and beneficial agricultural habitats with cross cutting benefits for many other plants and animals).
• 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; = Reservoir populations will only help insects if connectivity of improved habitats is undertaken concurrently. We URGENTLY need to address the importance of anthropogenic habitats and corridors (especially roads, rail, canals and their inherent connectivity), parks, open spaces and post-industrial land (quarries, ex-collieries, energy extractors and energy generators with land holdings) as a vital part of the landscape when it comes to invertebrate biodiversity. The acknowledgement of the importance of these “less likely habitats” – and subsequent works to improve their existing habitats - will work best in combination with a radical overhaul of farming practices and processes.
• Whether the threat to UK food security from insect decline receives sufficient cross-government priority; = If we regard wild pollinators as of principal concern and part of a balanced ecosystem which serves to increase UK food security then no, priority is lacking.
• Additional policy initiatives and solutions needed in the UK and internationally to reduce and reverse the trends in insect decline = Absolutely.
28 April 2023
Key references
https://www.bwars.com/
Ollerton, O. 2021. Pollinators & Pollination: Nature and Society. Pelagic Publishing.
Patterson, A. and Mclean, C. The precautionary principle at work: The case of neonicotinoids and the health of bees. Science and Public Policy, 46(3), 2019, 441–449.