Could also be that insects evolved to avoid long black patches of ground.

That doesn’t look likely, but also not impossible. That’s why we need the study.

Also, predator-prey systems (https://en.wikipedia.org/wiki/Lotka–Volterra_equations) can have fairly large cycles with huge population swings. That makes verifying that there really is a decline not _that_ easy. You can’t just repeat an insect count done 30 years ago and compare the numbers.

You can see the effect on the very same car very clearly. We have been traveling with a camping car from germany to romania. In germany we did not need to clean the windscreen at all. In romania we did it almost every day.

Your anecdote is very interesting, thank you!

> The research included vintage cars up to 70 years old to see if their less aerodynamic shape meant they killed more bugs, but it found that modern cars actually hit slightly more insects

https://www.theguardian.com/environment/2020/feb/12/car-spla...