I've never needed a magnifying glass to find the bugs that chew through leaves like that! And DE is for pests that are vulnerable to the tiny cuts it makes in their bodies. It doesn't work on soft bodied insects like caterpillars, but you'd have to check to see if it works on crickets and grasshoppers.
One thing to keep in mind with DE is it only works when it's dry.
One thing to keep in mind with DE is it only works when it's dry.