Benfica...that is the most retarded thing I have ever heard. Crickets don't carry ich, fin rot, dropsy, anchor worms or any of the other parasites and disease fish can get. Wild one are risky due to chemicals like pesticides but the ones in the LFS don't have that one them.
When I first got my oscar it was when I was at college and the place was overrun with ladybugs. My fish ate a lot of ladybigs with no ill effect and as long as i have been killing the things I have yet to see (or smell) any kind of dnagerious secretion.