Both can most likely be found in a number of Insectariums in zoos, The katydid I am about certain of.
This question Again. Attempts have been made, but no place holding them currently. There are some wild ones around the Singapore zoo though.
Actually, I'm not so sure of the Titan beetle as I have not seen it mentioned at any zoo or insectarium website. You were right with the Katydid on the other hand, which I found is at the St. Louis zoo. Should've done my research better... Its my 'home' zoo
Milwaukee and Cleveland at least had Muskie, don't know if they do still. Chain Pickerel is around but not super common.
I went to Maryland Zoo in 2012. Bog turtle exhibit was a literal replica of a bog outdoors, so the turtles were too tiny to spot. Has the exhibiting situation changed?
No idea Maryland just came up when I googled it but from what I know about the Maryland Zoos Maryland Wilderness area no.
Milwaukee's Muskie is bts. Minnesota Zoo keeps them Reiman Aquarium and SEA LIFE Minnesota keep them as well (not 100% sure on those two though).
Are there white belted black and white ruffed lemurs in the US? Zootierliste records many in Europe, but what about this side of the pond?
Are Belted or Ringed Kingfishers anywhere in captivity, whether zoos or rescue centers? And on the note of freshwater birds, are any grebes in American zoos or aquariums?