EU agriculture is also pesticide and insecticide heavy and only getting worse lately. Another problem (in Eastern Europe) is the use of banned chemicals, usually imported from Turkey or China. How do I know?

1. I used to keep bees for ~20 years. Saw a gradual decline in population ~5 years ago and now they are all dead. Same for most of the people in my community, except a few of them that do kind of "industrial" beekeeping, which requires lots of attention and is not feasible for a hobbyist.

2. When I asked some of the smaller farmers in the area why this is happening, they told be about the illegal imports that many are doing to stay competitive.

3. Tried complaining to authorities several times in the past. Whether out of negligence or corruption, they simply don't care.

Lots of non-GMO and Organic farmers use stuff that's just as bad as round up. They're kidding themselves if they don't think they are. Nature is full of quite deadly chemicals not made by man, but the "eco farmers" complete ignore that and act like "natural" pesticides are safer than man-made ones.

I'd guess that that monoculture, pesticides and fertiliser make up the bulk of the insect problem.

However, in terms of potential for unforeseen catastrophe, I'd leave GMO in the list. Our understanding of how small genetic changes can affect ecosystems in unintended ways is far, far from thorough. W don't even understand how small genetic changes affect us, never mind a biome filled with biomes.

Catastrophe is probably too strong a word, but I agree with the main idea here. The folks worried about human health effects are barking up the wrong tree. The risks (if there are any) are probably ecological, not medical.