New data suggest that insect life in Wales continues to decline, despite a hot summer

The troubling extent of insect declines has been highlighted once again by the results of the 2025 Bugs Matter citizen science survey published this week.

The latest data show that the number of flying insects sampled on vehicle number plates across Wales has fallen by a staggering 55% in just 5 years.

Bugs Matter, the annual survey from Buglife and Kent Wildlife Trust, has captured the imagination of citizen scientists across Wales. Using the simple but ingenious method of monitoring insect splats on vehicle number plates, the project provides crucial data about insect abundance.

Analysis of records from more than 1,500 journeys in Wales shows an alarming annual average decline in bug splats of 18%, since the survey began in 2021.

As COP30, the 30th UN climate conference, draws to a close in Brazil this week, world leaders have been discussing priority actions to tackle climate change, one of the key drivers of insect decline.

Insects are critical to ecosystem functioning and services. They pollinate crops, provide natural pest control, decompose waste and recycle nutrients, and underpin food chains that support birds, mammals and other wildlife. Without insects, the planet’s ecological systems would collapse.

Clare Dinham of Buglife said: “You might expect that the sunny Spring and hot Summer in 2025 would give insect numbers a boost, however the Bugs Matter data suggest otherwise.

“Despite apparently favourable conditions for insects to thrive we have recorded a fifth year of significant decline. Insects might be small, but they are incredibly important to maintaining healthy environments, and delivering the services that we and other animals rely upon – from healthy soils and clean rivers to pollinating crops.

“Losing 55% of our insect life is potentially catastrophic. Urgent action is needed to restore nature at scale and reduce threats like pesticide use, habitat loss, and climate change.”

The new data show decreases in insect splats across all regions of the UK, with the sharpest falls between 2021 and 2025 recorded in England at 60% and Scotland at 59%, while a 56% decrease was shown in Northern Ireland and a 55% decrease detected in Wales.

Rosie Bleet of Kent Wildlife Trust added: “These results are extremely concerning, particularly if insect splats serve as an accurate measure of insect populations.

“This is a red flag for the state of nature in Wales that shouldn’t be ignored. A yearly decrease of 18% is really alarming.

“It is vital that we continue to run Bugs Matter next year and beyond. We’re so grateful to all of the citizen scientists who were involved in the survey this year, collecting more data than any other year.

“We need even more of you to get stuck in next year and help track the numbers of these important creatures.”

Citizen scientists logged more than 10,000 journeys across the UK via the Bugs Matter app in 2025, covering nearly 481,000km; with more than 700 new users signing up to the app.

They saw citizen scientists in Wales logging nearly 10,000km and recording journeys from Holy Head to Barry.

In addition to this citizen scientists also recorded journeys in the Shetland Islands for the first time; meaning Bugs Matter participants surveyed as far southwest as Land’s End up to John O’Groats and beyond. The group extended their thanks to everyone who has taken part this year and helped to collect this vitally important data and encourage even more people to take part in 2026.

Visit the Buglife website to download the app today.