One thing to note on biomass and availability is that one of the few insect dishes in France and Germany till the 1950s, Mai Bug soup, was only made because of large beetle swarms in spring.

They're actually called cockchafers in English.

I had to research this because your mention of the soup brought up childhood memories of chocolates like this. I always got them as a treat on Easter when i was a kid. Most of the chocolates where eggs and bunnies, stuff that makes obvious sense for Easter, but there was always a chocolate bug in the mix and i asked my parents what was up with that. And they were like "it's because of bug soup" and i thought they were doing a bit.