That's a long time. Maybe you could get one of those boxes of crickets. They have live crickets and they have a small opening like a door to tap crickets out. You could open the door and hope only a few come out at a time. Bad thing about crickets is that they bite. That is why we usually remove any uneaten ones after the frogs/toads have eaten.

Another option is to sink a glass or ceramic bowl to substrate level and put some worms into it. Then they could eat from the bowl when they're hungry.