I have a lipstick plant with red tubular blooms but I noticed that the tips and sometimes near the base of the bloom is eaten away, mostly it's the tips though.

I opened the blooms but I don't see any bugs or anything, I even picked one off at night and put it under the light to see if the bugs were nocturnal, I could see them, but I saw none at that time either.

I want this plant for the hummers, so any safe things I can do to rid this problem would be appreciated.