What Whiteflies Are Doing to Your Trees and Palms

Q: Can whiteflies kill a tree?

Rarely, if the tree is large and healthy. The University of Florida whitefly FAQ says whiteflies do not typically kill large, healthy trees, shrubs and palms, while young, newly planted or unhealthy plants are more at risk. Severe, long infestations can still cause decline, defoliation and branch dieback. Keeping trees watered and fertilized helps them tolerate feeding.

Q: Should I cut down a tree infested with whiteflies?

Usually not. UF/IFAS says you do not need to prune or remove an infested tree. If pruning is needed for other reasons, do it before any insecticide treatment and follow good arboricultural practices. Remove branches that are clearly dead. Cutting down a mature shade tree because of whiteflies trades a temporary problem for a permanent loss.

Q: Are whiteflies on my mango or avocado tree a problem for the fruit?

They stress the tree more than the fruit. Mango and avocado are among the hosts of rugose spiraling whitefly, whose honeydew and sooty mold coat leaves and anything below. Wash fruit before eating as usual. Treating fruit trees requires products labeled for that use, with pre-harvest intervals, so tell your technician which trees you harvest from.

Q: Do whitefly treatments on trees harm bees?

It depends on the product, method and tree. The University of Florida whitefly FAQ notes that soil or trunk applications reduce direct contact with beneficial insects, but bees can still be exposed through pollen from treated flowering plants. Many affected trees, like ficus, are not bee-pollinated, while fruit trees flower heavily. Foliar pyrethroids may pose a greater risk to bees than soil or trunk treatments.

Q: Why do whiteflies come back on my trees every year?

Because they live in the whole neighborhood. FDACS notes that neighboring untreated trees can reinfest treated ones, so reapplication is often needed. South Florida's warm weather also lets whiteflies breed for most of the year. Learn more in why whiteflies spread so fast in South Florida.

Key takeaways

Rugose spiraling whitefly, first found on gumbo limbo in Miami-Dade in 2009, has more than 60 host plants, led by gumbo limbo and palms.
Whiteflies do not typically kill large, healthy trees and palms; young, newly planted or stressed trees are more at risk.
For large trees, sprays rarely reach every leaf; FDACS reports good control from systemic soil drenches or trunk injections.
Untreated neighboring trees can reinfest treated ones, so treatment often has to be repeated.

In this article

Which Whiteflies Attack Trees in South Florida?
What Whiteflies Are Doing to Your Trees
Can Whiteflies Kill a Tree?
How to Check a Tall Tree for Whiteflies
How to Help a Whitefly-Stressed Tree
Why Sprays Don’t Work Well on Large Trees
When to Call a Professional
Frequently Asked Questions

Whiteflies are slowly draining your trees. Thousands of them feed on the undersides of the leaves, pulling out sap the tree needs for new growth, while their sticky honeydew feeds a coat of black sooty mold that shades the leaves. The tree rarely dies, but it thins out, drops leaves, loses branches and spends its energy on survival instead of growth.

In South Florida, the main culprits on trees are the rugose spiraling whitefly on gumbo limbo, palms and fruit trees, and the ficus whitefly on banyans and other ficus trees. Because the damage happens high above eye level, many homeowners only notice it when their car, patio or pool is covered in sticky residue. This guide explains what is happening up in the canopy and what you can do about it.

Tiny whiteflies and a sticky sheen covering the underside of a palm frond, showing damage to palms.

Which Whiteflies Attack Trees in South Florida?

Rugose Spiraling Whitefly

The rugose spiraling whitefly is the tree specialist. It was first collected on gumbo limbo in Miami-Dade County on March 11, 2009, and more than 60 plant species are now recorded as hosts, according to the Florida Department of Agriculture and Consumer Services. FDACS lists gumbo limbo and palms, especially coconut, as the most seriously affected, along with avocado, Florida black olive and Calophyllum.

Other recorded hosts include areca and Veitchia palms, cocoplum, wax myrtle, live oak and mango, according to the UF/IFAS Tropical Research and Education Center. Adults are about 2.5 mm long, roughly three times larger than other whiteflies in the U.S., and females lay eggs in white waxy spirals on the undersides of leaves.

Ficus Whitefly

The ficus whitefly feeds only on ficus, but that includes large trees as well as hedges. UF/IFAS reports it on at least eleven ficus species, with weeping fig (Ficus benjamina) appearing to be its preferred host. It was first detected in the United States in 2007, and UF/IFAS links its feeding to leaf drop, yellowing, honeydew, sooty mold, branch dieback and, in severe cases, the death of host plants.

Bondar’s Nesting Whitefly

UF/IFAS researchers call Bondar’s nesting whitefly the second most prevalent whitefly on ficus hedges in Florida. It was detected in the state in 2011, also feeds on citrus, guava, sugar apple and coconut, and UF/IFAS warns that untreated infestations may eventually kill the plant.

Tree or palm	Main whitefly	What you see
Gumbo limbo	Rugose spiraling	Wax spirals, heavy sooty mold, sticky ground below
Coconut and adonidia palms	Rugose spiraling	White wax under fronds, black fronds
Black olive	Rugose spiraling	Dripping honeydew on cars and pavers
Mango and avocado	Rugose spiraling	Wax and mold on leaves, ants on trunk
Banyan and weeping fig trees	Ficus whitefly	Yellow leaves, then thinning canopy
Citrus and guava	Bondar’s nesting	Round wax “nests” on black leaves

You can compare photos of each species in our whitefly pest library.

What Whiteflies Are Doing to Your Trees

Draining Sap

Whiteflies feed with needle-like mouthparts, and FDACS explains that feeding removes water and nutrients and stresses the plant. On a heavily infested tree, the rugose spiraling whitefly can cover almost the entire underside of the leaves.

Shading Leaves With Sooty Mold

Honeydew falls on leaves below and feeds black sooty mold, which reduces leaf function. On palms and gumbo limbo, the wax and mold together can make the canopy look gray or black. The same problem on hedges is covered in why your hedge is turning black.

Thinning the Canopy

Leaves yellow and drop early, especially on ficus. UF/IFAS notes that whiteflies in general can cause plant decline, defoliation and branch dieback. For ficus, leaf drop shows up only after several months of infestation, so a thinning banyan has usually been infested for a while.

Raining Debris on Your Property

FDACS reports that rugose spiraling whitefly honeydew, wax and dead adults fall on cars, patios and furniture and can clog pool filters, and that the sooty mold attracts stinging ants and honeydew wasps. A single infested tree over a driveway can make a property feel dirty.

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Can Whiteflies Kill a Tree?

Usually not, if the tree is large and healthy. The University of Florida’s whitefly FAQ says whiteflies do not typically kill large, healthy trees, shrubs and palms, but young, newly planted or unhealthy plants are more at risk. Even for the rugose spiraling whitefly, UF/IFAS noted when it first arrived that the actual effect of an infestation on a plant’s health was unknown.

The real risk is accumulated stress. A tree that is also dealing with drought, heavy pruning, root damage from construction or storm damage has fewer reserves. In most cases, ficus trees and hedges grow new leaves once the whitefly is controlled; dead branches should be pruned out. For the cost side of waiting too long, see why ignoring whiteflies can cost you more.

Toro tip: Look up, not just around. Sticky windshields, a black film on pavers, or ants trailing up a trunk are often the first signs of whiteflies in a tree too tall to inspect from the ground.

How to Check a Tall Tree for Whiteflies

You cannot turn over leaves 30 feet up, but you can still read the signs from the ground:

Check the lowest branches. Turn over a few leaves you can reach and look for white wax spirals, flat yellowish nymphs and empty pupal cases.
Look at fallen leaves. Leaves on the ground often still carry wax spirals or nests underneath.
Watch the ground and cars. Fresh, sticky spots on windshields, pavers or patio furniture mean insects are feeding overhead right now.
Follow the ants. Ants trailing up and down a trunk are usually collecting honeydew.
Compare with neighbors. If trees of the same species next door are infested, yours are likely next.

How to Help a Whitefly-Stressed Tree

You do not need to remove or heavily prune an infested tree, according to UF/IFAS. Instead:

Water and fertilize properly. Healthy trees tolerate infestations better.
Avoid unnecessary pruning. Leaves are the tree’s energy supply. If pruning is needed, do it before any treatment and follow good arboricultural practice.
Do not judge by old leaves. Mold and yellow leaves remain for a while after the insects are controlled.
Protect natural enemies. A parasitic wasp, Encarsia guadeloupae, and a small beetle, Nephaspis oculata, attack the rugose spiraling whitefly, according to FDACS. Broad-spectrum sprays kill them.

Why Sprays Don’t Work Well on Large Trees

Spraying water or soap on infested leaves can dislodge many whiteflies, but FDACS notes that this is temporary and impractical for large trees and palms. Reaching every leaf underside in a 30-foot canopy is not realistic, and drift onto neighboring yards is a concern. That is why DIY attempts on trees so often fail; our article on common mistakes in whitefly treatments explains more.

For trees and palms, FDACS reports that good control can be achieved with systemic insecticides applied as soil drenches or trunk injections. Because untreated neighboring trees can reinfest treated ones, reapplication is often needed.

Safety note: Treatments for fruit trees must be labeled for that use, and the label sets how long you must wait before harvest. Bees can be exposed through pollen from treated flowering trees, so timing and method matter. Tell your technician which trees you harvest from and whether children or pets use the area.

When to Call a Professional

Call for an inspection if you see white wax spirals under palm fronds or gumbo limbo leaves, a thinning ficus canopy, ants trailing up a trunk, or honeydew raining onto cars and patios. A professional can identify the whitefly, check how many trees are involved and choose a method that fits each tree’s size and use.

Toro’s whitefly control service begins with a free inspection of your ficus, palms and trees, including the undersides of the leaves, to identify which whitefly you have and how heavy the infestation is. You get a clear plan and a quote before any work begins, followed by treatment and monitoring. If you are weighing the bigger picture for your yard, read how whiteflies threaten your landscape and property value.

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Frequently Asked Questions

Can whiteflies kill a tree?

Rarely, if the tree is large and healthy. The University of Florida whitefly FAQ says whiteflies do not typically kill large, healthy trees, shrubs and palms, while young, newly planted or unhealthy plants are more at risk. Severe, long infestations can still cause decline, defoliation and branch dieback. Keeping trees watered and fertilized helps them tolerate feeding.

Should I cut down a tree infested with whiteflies?

Usually not. UF/IFAS says you do not need to prune or remove an infested tree. If pruning is needed for other reasons, do it before any insecticide treatment and follow good arboricultural practices. Remove branches that are clearly dead. Cutting down a mature shade tree because of whiteflies trades a temporary problem for a permanent loss.

Are whiteflies on my mango or avocado tree a problem for the fruit?

They stress the tree more than the fruit. Mango and avocado are among the hosts of rugose spiraling whitefly, whose honeydew and sooty mold coat leaves and anything below. Wash fruit before eating as usual. Treating fruit trees requires products labeled for that use, with pre-harvest intervals, so tell your technician which trees you harvest from.

Do whitefly treatments on trees harm bees?

It depends on the product, method and tree. The University of Florida whitefly FAQ notes that soil or trunk applications reduce direct contact with beneficial insects, but bees can still be exposed through pollen from treated flowering plants. Many affected trees, like ficus, are not bee-pollinated, while fruit trees flower heavily. Foliar pyrethroids may pose a greater risk to bees than soil or trunk treatments.

Why do whiteflies come back on my trees every year?

Because they live in the whole neighborhood. FDACS notes that neighboring untreated trees can reinfest treated ones, so reapplication is often needed. South Florida's warm weather also lets whiteflies breed for most of the year. Learn more in why whiteflies spread so fast in South Florida.

Sources

The Rugose Spiraling Whitefly, Aleurodicus rugioperculatus Martin, a New Exotic Whitefly in South Florida (Hemiptera: Aleyrodidae), Florida Department of Agriculture and Consumer Services
Rugose Spiraling Whitefly (previously Gumbo Limbo Spiraling Whitefly): A New Whitefly in South Florida, UF/IFAS Tropical Research and Education Center
Frequently Asked Questions (FAQs), University of Florida Entomology and Nematology Department
Ficus Whitefly, Singhiella simplex (Hemiptera: Aleyrodidae), UF/IFAS Tropical Research and Education Center
Ficus Whitefly Management in the Landscape, UF/IFAS Tropical Research and Education Center
Balios Eulophid Baeoentedon balios Wang, Huang & Polaszek (Insecta: Hymenoptera: Eulophidae), UF/IFAS Extension
Bondar's Nesting Whitefly - Paraleyrodes bondari, UF/IFAS Extension

Educational content. This article is for general information about pests in South Florida and is not medical, legal or professional advice. If you have a bite, sting or allergic reaction, contact your doctor; in an emergency, call 911. Pest problems vary from home to home, so a licensed professional should inspect before treatment. When using any pesticide, always read and follow the product label.