I am not an expert on the subject, but I have been growing tomatoes for the last 35 years and have noticed in the last few years that many of the flowers don't get pollinated - they are wasted - as if the plants were growing indoors.

It was rare to see flowers gone to waste. Now is common. Local people blame the pesticides used in commercial crop growing. Somehow, these pesticides spread and eliminate(?) insects. However, pesticides are on the decrease, maybe that will help the insects to flourish again.

@ Michael  Thank you for your thoughts - exactly what I was hoping to stimulate from the posting.  Where pollinated foods make up around 80% of what we eat and buy at the grocery store, this is really a worrying situation.  Neonicotinoids are implicated in much of this and there's lots of evidence that these cause issues - and these are actually increasing in usage year-on-year (on a worldwide basis).

As a layman on this subject, I can only comment that I think it is generally thought that as insects pollinate our plant food, we should not be inadvertently poisoning them with agrichemicals.