Bugs Matter Citizen Science survey shows further decreases in insect numbers in Wales

Wednesday 24th April 2024

The troubling extent of insect declines in Wales has been highlighted once again by the 2023 Bugs Matter citizen science survey published today. The new report reveals that the abundance of flying insects sampled on vehicle number plates has fallen by a staggering 79% in Wales since 2004.

The Bugs Matter survey, led by Kent Wildlife Trust and Buglife, is supported by a UK wide network of volunteer citizen scientists who record insect splats on their vehicle number plates after journeys. Since the first reference survey in 2004 led by RSPB, analysis of records from nearly 26,500 journeys across the UK shows a continuing decrease in bug splats, with the number of splats in 2023 decreasing by an average of 78%.

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.

Dr. Lawrence Ball of Kent Wildlife Trust stated: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 the UK that shouldn’t be ignored. A decrease in the number of insects sampled of more than 75% in less than two decades is really alarming, and we’re seeing fewer insects being sampled every year! It is critically important that we continue to run Bugs Matter, and we’re so grateful for the ongoing commitment of citizen scientists to the Bugs Matter survey, which led to more data in 2023 than in any previous year.

The new data shows decreases in insect splat rates across all regions of the UK, with the sharpest fall recorded in England at 83% since 2004,closely followed by Wales where there has been a 79% decrease over the same period.  Scotland saw a 76% drop, while Northern Ireland, with limited data, showed a 54% decline between 2021 and 2023.

During 2023 Welsh citizen scientists recorded a total of 408 journeys, covering nearly 7500 miles, through the Bugs Matter app; with the number of insect splats between 2022 and 2023 alone decreasing by a worrying 26%.

Clare Dinham of Buglife added:The latest Bugs Matter data suggests that the abundance of flying insects in our countryside has dramatically fallen.  The consequences are potentially far-reaching, not only impacting the health of the natural world, but affecting so many of the free services that nature provides for us. The Bugs Matter findings are similar to other studies which have documented declines in insect abundance from around the world.  Human activities continue to have a huge impact on nature – habitat loss and damage, pesticide use, pollution, and climate change all contribute to the decline in insects.  Society must heed the warning signs of ecological collapse, and take urgent action to restore nature”.

The report’s authors caution that further long-term monitoring is needed to reliably estimate trends, but stress that the current pace of decline is unsustainable. By taking part in the Bugs Matter survey each year, citizen scientists can provide crucial data to better understand insect population patterns. They call for urgent action to address drivers of insect declines like habitat loss, unsustainable agricultural practices, and environmental pollutants.

Clare Dinham concluded:Thank you to everyone who took part in the Bugs Matter survey in 2023.  Without your help we would not have this crucial data on the health of our insect populations and our environment. We are relaunching the survey in May this year, and hope that lots more people will join in.

The Bugs Matter survey will continue annually to generate crucial data on flying insect populations across the UK. It is quick, free and easy to get involved – just download the free mobile phone app, and start recording insect splats on vehicle journeys.

2024 will see the survey season extended to firstly capture even more valuable data and secondly to potentially account for changes and variations in weather patterns and possible insect emergence events; participants in Wales can now record journeys and submit date between Wednesday 1 May and Monday 30 September.


  • The Bugs Matter 2023 Full Technical Report can be found here
  • The Bugs Matter 2023 Summary Report can be found here