Insect-friendly driving

SIR – Monika Butler (Letters, August 14) suggests that the absence of dead insects on her car’s windscreen after an evening drive is down to the insect world shrinking.

Might I offer an alternative suggestion? Road congestion in Britain is so dreadful after years of neglect and planning that there are simply fewer opportunities to drive fast enough to enable this to happen.

Having just driven back from the south of France, on relatively empty and roadwork-free autoroutes, I can report that the windscreen of my car is as plastered in dead insects as ever. Edward Jones Twickenham, Middlesex

SIR – Insect-free windscreens do not necessarily indicate a decline in insects, but more likely an improvement in vehicle aerodynamics.

During a long drive many years ago, my wife complained that the windscreen on her side was covered in dead insects – yet my side was not.

The difference: one normal wiper and one with a deflector to allow the airflow to press it harder to the screen. Since then vehicle shapes (and wipers) have changed significantly, and it is likely that most insects are swept up and over before reaching the windscreen. Steve Walker Manchester