I have a true key lime tree that was grafted from my parents tree in key west Fl. It has been blooming and giving us nice limes. here recently it has been dropping some leaves and the small limes that were forming are falling off. I've also noticed there are little white insects on the trunk and branches. They resemble a shark fin on top of its body, as you try to touch them they just roll over around the branch away from your finger. they do fly,and I've sprayed them with water only for them to return. they hold there wings up when at rest and its in the shape of a fin. Does anyone know what they might be and if so how do you get rid of them? And are they harmful to the tree. thanks in advance. Any help will be appreciated. Ialso did'nt mention I have yet to plant the tree in the ground ,it is in a 10 gal bucket right now. the tree is about 3 feet high and about 1 1/2 years old. thanks.