Some CMer friends of mine (Charlotte Mason Education folks) were on a nature walk today and these little guys showed up and were discussed. I was sad I missed the walk, but the discussion reminded me of some thing I had learned from a story about an bio-agricultural fiasco...way back while doing biology with my freshman in high school. Yes, we used what would be termed a "children's book" (along with many other resources from children's books to books written for adult scientists) and you know what? I connected with it as an adult and still remember it. (No snide thoughts about what that may or may not say about my adult status!) I'll share and you can go and do your own research if it sparks your curiosity...
It sounds like you all had a wonderful day! I'm so sorry to have missed :(.
A note on the Asian beetles, could be in one of the links I haven't read yet, but they are not indigenous and were introduced to control pests for crops (corn I think). Unintended results... That worked apparently, but because of their protection mechanism (smell/taste and shell) their predators are lower (some birds won't eat them I think). I was told by my pest control guy, (sorry, I know that's a grave offense :)), that their migration pattern will mean less infestation this year and forward. Haven't seen as many inside yet, so maybe so. Asian beetles are orange instead of the ladybug red and they also bite :(. Once introduced, you can't send them back. Think Asian carp, kudzu, starlings. There's a great book in the biology study guide about toads in Australia - yes, it's people in general, not just Americans. The book is Toad Overload by Patricia Seibert. I think there might be an object lesson there with unintended consequences :).
Now, I'm just sharing something I learned through my reading. If you are interested, you can look it up. Just because I saw the connection, and you and I might find it interesting, doesn't mean you have to add it to what your kids are doing. It might just be something to keep in mind IF they ask about it or it actually fits into a specific study. Don't Overload your children with a bunch of extra information, there might be unintended consequences :)