I think that some synanthropic insects will thrive, even running amok as competition disappears and so do their predators.

In fact birds that previously didn’t show any synanthropic behavior have adapted as well, like hawks hunting during the night as city lights allow them to do so. So maybe we will se more behavioral changes in human environments.

Great tits do forage during winter instead, so they could expand this behavior longer, however caterpillars are their favorite for their chicks due the protein density.

I’m trying to be hopeful, but as you say, as long as the insect biomass is dropping so rapidly, I don’t see them surviving :(