Hello, Donna, I have not seen that sort of thing on my tree. It may well be some sort of canker. I would advise taking a sample to your county agricultural office, to see if they are able to advise you. Have you considered spraying your tree with something like insecticidal soap? We are currently having our tree farmed by ants, which "tend" mealy bug like creatures which we will have to spray for with malathion. Fortunately, our Bearss is strong enough to hold on for a while until our crop of limes is in over the course of the next 4-6 weeks, as I really don't like to spray nearly mature fruit, unless we absolutely have to. Ron