As of 2012, there are two distinct Whitefly species which are causing problems here in south Florida. The Ficus Whitefly (Singhiellia simplex), and the Rugose Spiraling Whitefly (Aleurodicus rugioperculatus).  The Ficus Whitefly has been an ongoing problem for the past for six or more years, but the Rugose Spiraling Whitefly has really only become evident during the last two years. It was previously known as the Gumbo Limbo Whitefly, as it is often seen on Gumbo Limbo (Bursera simaruba) trees. It is also commonly seen on Coconut palms (Cocos nucifera) and Black Olive trees (Bucida buceras).

Gumbo Limbo Whitefly Infestation

While the Ficus Whitefly will certainly kill host plants if left untreated, it seems that the Spiraling Whitefly will not usually kill host plants, but it does cause them, and anything beneath them, to look unsightly, by covering the undersides of the leaves with silvery white insect casings and the tops of the leaves, branches and stems with black mold.

The treatment for both insects is similar, in that a contact insecticide, horticultural oil, or soap may be used on adult insects on the leaves, and a systemic insecticide is required to protect the plant from re-infestation. There is at least one natural enemy for Spiraling Whitefly, a parasitic wasp, but its effectiveness has been minimal at best, probably due to overuse of insecticides.

My recommendation for Ficus Whitefly has always been the removal of infected plants and replacement with a non-Ficus species.

For Spiraling Whitefly, I recommend removal of small infected plants and treatment of large trees if the infestation becomes a problem.

Please see these fact sheets for more information on Rugose Spiraling Whitefly and Ficus Whitefly