The reasons behind 'significant' drop-off in insect splats on car windscreens in Scotland

Bug experts have said an “alarming” drop in insect splats on cars across Scotland in the past five years is indicative of insect declines across the country.

Latest data from conservation groups shows the number of flying insects sampled on vehicle number plates across Scotland has fallen by a staggering 65 per cent since 2021.

The Bug Matter survey is based on the '”windscreen phenomenon” - a term given to the anecdotal observation that people tend to find fewer insects squashed on the windscreens of their cars now, compared to in the past.

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Insect splats have shown a steep decline in Scotland in the last five years | Dan TP

The losses are believed to be due to habitat loss, pollution, pesticide use and changes in climate.

Results came from a network of volunteer citizen scientists who recorded insect splats on their vehicle number plates from more than 25,000 journeys across the UK since 2021.

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While the sharpest fall across the UK was recorded in Scotland, England saw a 62 per cent drop, Wales 64 per cent and Northern Ireland was at 55 per cent.

Conservationists, however, said the rate at which insect splats are declining has slowed in the past few years. The survey was carried out by Buglife Scotland in partnership with the Kent Wildlife Trust (KWT).

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Dr Lawrence Ball, of KWT, said: "The results from the Bugs Matter survey are really concerning.

“We are probably detecting insect declines as they are happening, which reflect the enormous threats and loss of wildlife more broadly across the UK. These declines appear to be happening at an alarming rate and without concerted action to address them we face a stark future. Insects and pollinators are fundamental to the health of our environment and rural economies.”

Those behind the study said more action needed to be taken to create “more and bigger areas of habitats” and provide nature corridors for wildlife.

Dr Ball added: “This huge decrease in insect splats over such a short time is really alarming. After an initial increase in Scotland between 2021 and 2022 (+17 per cent) the number of splats decreased in 2023 (-61 per cent), but this rate has slowed in 2024 (-24 per cent).

“It’s most likely that we are seeing the compounding effects of both a background rate of decline as well as a short-term cycle of decline, perhaps linked to the extreme climate in recent years. Continued support from citizen scientists is key to revealing the overall trend in insect numbers.”

Rebecca Lewis, of Buglife Scotland, said: "The latest Bugs Matter data suggests that the abundance of flying insects in our countryside has fallen again. But we can turn the tide. We need more space for nature – so more habitats restored at scale, connected across whole landscapes. We need safer places for wildlife, which means reducing our use of pesticides and other pollution of land and freshwater.”

This year’s survey for insect splats launches on May 1 and will run until September 30.

By taking part in the Bugs Matter survey, which has received funding from the RSPB, Openreach and Amazon Web Services, citizen scientist data helps with a better understanding of insect population patterns.