Poll-A-Gen: A century of genome diversity in UK insect pollinators

Insects dominate terrestrial and freshwater ecosystems across the globe. They perform a diverse range of roles and provide ecosystem services valued at billions of pounds each year. One of the most important of these services is pollination.

Insect pollinators are an essential element of many ecosystems. They play a critical role in ensuring the reproductive success of different plant species. This includes a range of crop species, such as apples, as well as wildflowers.

Although domesticated honeybees are important for pollination, much of the work is done by wild species, including bumblebees, wasps and hoverflies. In the UK, the Wildlife Trust estimates that 85-95% of our insect-pollinated crops rely on wild pollinators [1].

However, despite their significant economic and ecological value, it is no secret that UK insect numbers are declining. A study by conservation charities Buglife and the Kent Wildlife Trust in 2022 estimated that flying insect numbers had fallen by as much as 60% over the last twenty years in the UK. This trend is thought to be driven by rising temperatures, fragmented habitats and excessive pesticide use in agriculture [2]. Yet studies which measure the total number of individuals are the only way to measure changes in insect populations.

Another approach, which is increasingly important in insect conservation, is to determine genetic diversity. If a particular species has low genetic diversity, we can infer that its population size is probably quite small.

If we can also see that the population has gene variants that protect against pesticides or rising temperatures, we can also infer that the population is reacting to environmental change. If we can also incorporate some older museum specimens, we can see how much genetic variation there was at different times in the last century, building up an idea of the rate at which diversity is being lost in different parts of the UK.

Scientists at the Natural History Museum have been funded by the Natural Environment Research Council (NERC) to do exactly this kind of work, in a project called Poll-A-Gen.

We are using our extensive network of sample providers, our knowledge of the natural world, and our expertise in recovering highly degraded DNA from museum specimens to understand how the genomes of bees, wasps, and hoverflies have changed over the last 100 years.

This data will help our project partners design better policies and strategies for insect conservation and support research on crop pollination in the future.

Poll-A-Gen is currently the largest study of museum insect population genomics in the world, but we hope that our methods will inspire others to generate historical baselines of genome diversity for other species and in other countries.

Our role in the project

Collaborating with internal and external stakeholders, the Natural History Museum team will be leading all aspects of this project, in terms of the sampling (for both modern and historical material), the genomic data generation (in the museum's Molecular Labs) and the subsequent bioinformatic analysis.