Although it is difficult to diagnose a problem without examining an actual sample, from your description this sounds like scale insects. Scales insects feed by sucking sap from the plant. Lady bugs (lady beetles), in both their adult and larval stages, are one of the types of insects that feed on scale insects. Several species of lady bugs are found in Florida, including some that lack spots. If you see several lady beetles on the tree it may be best to allow them to continue feeding undisturbed and thereby helping to control the scales. If there are very few of them and large numbers of scales you may want to spray with a light horticultural oil. The oil acts to suffocate the scales and is considered an environmentally friendly method of insect control.

More photos of lady beetles can be found here:
http://entnemdept.ufl.edu/creatures/beneficial/lady_beetles.htm