Yesterday, I was bitten by a metallic yellow fly; today, the swelling is worse and it itches like crazy. This has happened before, but when I applied the plantago root poultice that I usually use, it didn t work . This remedy has worked for me many times, but this is the first time I ve had to make more than one application of the poultice. Am I gaining a tolerance to the poultice, and if so, what other herbs could I consider for a back-up?