Insect population declines, are widely reported. And seem obvious on windscreens, here in the UK, and DK. Also reports from far away places, eg Africa seeing declines.
So, a question: "Could the level of insecticides, in the global atmosphere, have achieved gas concentration that is enough to harm/impair/or even kill insects?"
Insecticides such as I wonder, the nerve agents (some quite persistent) with high vapour pressure and hugely toxic to insects (in synthetic pyrethroids; pyrethrins; and organophosphates such as malathion; parathion; dichlorvos; carbamates; phosphine). Or even, perhaps, in neo-nicotinoids (#NEONICS).
A kind colleague, in Cambridge, who measures trace gases thought it was improbable. And observed that it would require (o-o-m) a sample of 200 litres, accumulated by a liquid N2 cold trap, and would be messy/tricky to to get the measurement. So I thought no more.
The marvels of GC-MS, and the ppb levels that might be detected/enumerated, in the sample trapped from 200l would be a possibly interesting exercise. And maybe valuable?
However, other chemicals have achieved rather damaging levels in the atmosphere (and in oceans). One notably caused a large "ozone hole" over Antarctica. And, one might observe, in the days of cold war #MAD there were diagrams of vapour trails across Europe/Eurasia from chemical warfare. But it did not occur to the author, apparently, that actually and inevitably the many 500km-800km "vapour trails" he drew would simply merge, and gas everyone. There might be, on further reflection, similar misappreciations today?
www.nhm.ac.uk/discover/news/2019/february/the-world-s-insect-populations-are-plummeting-everywhere-we-look.html