No, it's down to the amount of insecticide that's used these days! That's a bad thing as insects are a vital food source for many small creatures, and of course many insects are also pollinators.
I think that is too simplistic a reason as pesticide usage has reduced if only as a financial factor in farmers activities. Many instecticides were banned some years ago. My cache would have made Saddam Husein look a good guy, although I rarely used what I had in store.
Other reasons are changes in farming practises, and denuding of the countryside. I was on Cherhill Down last week and looking over a large area and it was particularly noticeable how few hedges there were, few tress or copses, and how much monoculture was growing. When we had set aside the area had insects, birds, hare and deer, plus raptors. Now there's. just a small area managed by the National Trust. Britain has a particularly poor record in protecting its wildlife.
The elephant in the room is the gradual warming of the climate, which sees foreign species arriving, and for which native species have difficulty adapting. Heading off to avoid incoming!
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