Whiteflies and Sooty Mold on Parkland Hedges and Palms

Several whiteflies hit South Florida plants. One that gets a lot of attention is the rugose spiraling whitefly. The Florida Department of Agriculture's pest alert has a 2009 Miami-Dade collection on record, lists more than 60 host plants, and says gumbo limbo and palms, especially coconut palms, get hit hardest. Avocado and Florida black olive trees are on the list too.

The name comes from the egg pattern. Females lay eggs in spirals on the underside of leaves and cover them in white wax. If you flip a leaf and see white swirls, that's the sign.

Whiteflies suck sap and excrete honeydew, a sticky liquid that coats the leaves below. A black fungus called sooty mold grows on that honeydew. The mold doesn't infect the plant, but it blocks sunlight and makes everything look dirty.

Ants love honeydew. If you have ghost ants or white-footed ants trailing into the house, check the closest hedge. Treating the whiteflies can cut down the ants. See ant control.

Light cases can be hosed off and pruned. Heavy cases on big hedges and trees usually get a product applied to the soil or trunk that the plant takes up and carries to the leaves where the whiteflies feed. A provider who does lawn and ornamental work can tell you what fits your plants. Natural enemies, like tiny parasitic wasps, also help. FDACS notes that very dark brown puparia suggest the whiteflies have been parasitized.

• Look under leaves for white spirals and waxy fluff
• Check for sticky leaves and black film
• Watch for ants climbing the trunk or hedge
• Note which plants are hit worst