I never find any hellgramites big enough to attract any but small bass - and a lot of our lakes have minimum harvest sizes of 15” or 16” for largemouth bass.
1/2” - 1” larvae of most any type are great for bluegill, though.
Big katydids are very good for bass, but I usually only see half a dozen katydids per summer, and not all those where they can be caught.
Fully grown tomato hornworms are great bait too, but, you really don’t want them getting that big on your tomato plants!!! I’ve always wondered why someone didn’t make a soft plastic “worm” bait that looks like a hornworm. (Bright green is a very good bait color in general, as is white.)
Evidently, dad was catching some big ones. He’d have a net or screen & pick up rocks in the river where the hellgramites would be located, catching them as they were ‘flushed’ out. Dad was a teenager mostly when doing this so the time frame would have been in the 1930’s.