I helped an old dude clear out his garage last year. In the back was a big, old, still half-full 10L bottle of washer fluid that advertised how effective it was at clearing insects off the windscreen. He said that during the peak of Spring you couldn't drive more than fifteen minutes without using a few spritz to clear them, but at some point he just stopped having to refill with anything more potent that antifreeze. Personally, I honestly can't remember the last time I used my sprayers, but I'm sure it's been over a decade.
Insects are dying because we're killing them.
Which is surprising, because in North America they use 60Hz.