re: Where'd half the insects go?

Well we had a helluva hard winter, so I attribute the lack of caterpillars to that. As for the other bugs,I haven't noticed a decline at all. Did you notice the gnat invasion this past spring at all? I couldn't go outside without them biting. It was misery. I even had a huge vet bill for my dog getting hot spots due to gnat bites. I thought the gnats would never go away this year, and don't remember them being this bad ever.
If you have a vegetable garden, you know that the insect pest population is doing just fine. I had a bunch of bugs in my garden this year.
About the only insect I have noticed a huge decline in is the firefly population, and its drop is directly attributable to the mosquito abatement programs in the city.
Incidentally, I think the gecko population was hit hard by all the intense freezes last winter as well.