This has me stumped: something is decimating certain of my plants during the night - eating unbelievable amounts of foliage, while leaving neighboring plants untouched.

1st instance was 12" clumps of alfalfa completely stripped of ALL leaves overnight. I'm assuming some sort of caterpillar, since it ate leaves from between stems in the clump. Then I noticed broccoli leaves missing - 5" (or so) leaves eaten down to the stem, & a little papaya plant met the same fate - entire leaves gone in 1 night. They are nothing but sticks now = (

I rooted around the base of plants to see if it was cutworms, but can't find anything, & no slime trails to indicate snails or slugs. Edges of eaten areas on broccoli look torn, ragged, like grasshopper damage, but grasshoppers are nowhere right now. I realise it may be more than 1 culprit, but the M.O. seems so similar, I suspect 1 type of animal/insect is responsible. I'm picturing a mass of giant cutworms hiding somewhere around here, but I have not found any frass around or on the damaged plants.

There are no rabbits or squirrels here on this island, tho we do have rats & possums. I'm wondering if katydids might be responsible - tho I've ever known them to eat that much, that fast...?

Anybody have any clues/solutions, similar experience?