>Recent reports of dramatic declines in insect abundance suggest grave consequences for global ecosystems and human society. Most evidence comes from Europe, however, leaving uncertainty about insect population trends worldwide.

This makes me wonder how much of the decline in Europe is due to the ecological side effects of two highly destructive world wars. Mechanized, combined arms combat moves a lot of dirt around, via explosions, and tracked vehicles ripping up the soil, which would kill or disrupt a lot of insect's breeding/eggs. Large swaths of mainland Europe were carpet bombed, or subject to intense artillery fire. Additionally, after the war, reconstruction efforts would have disturbed even more soil and insect habit, coupled with the Green Revolution's increase in fertilizers, pesticides, etc.

If the insect population in Europe was previously devastated, or diminished by physical upheaval, then it wouldn't surprise me that the population as a whole hasn't recovered from, and is still losing ground to, the more pervasive insecticide and manufactured pollutants (ie all the plastic derivatives, BPAs, etc) that have become part of our environment.