Whitefly is a tiny sap sucking insect, closer to an aphid than a fly, that lives in clouds on the underside of leaves and rises in a white puff when the plant is brushed. In the UAE it gathers on five host plants above all others. This guide names those five, explains how to confirm whitefly, and sets out control for garden beds and for pots indoors.
What is whitefly?
Whitefly is a sap feeding true bug about 1.5 mm long, with four wings dusted in white wax. Adults sit and lay eggs on leaf undersides, and the flat, scale-like young stay fixed there feeding until they mature. Both stages drain sap and drop sticky honeydew.
Two species cause most of the damage here. The silverleaf whitefly, Bemisia tabaci, feeds on more than 600 plant species. The ficus whitefly, Singhiella simplex, arrived in the Gulf more recently and sticks almost entirely to ficus.
Tap the plant and watch. A drift of white specks that settles back within seconds is whitefly.
The young are harder to see: pale green ovals under 1 mm, flat against the leaf like a speck of scale.
The 5 UAE plants whitefly concentrates on
Whitefly in UAE gardens concentrates on five host plants: ficus hedges, hibiscus, lantana, citrus trees and the tomato family in vegetable beds. A garden without any of the five sees far less of it, and a garden with all five carries whitefly for most of the year.
- Ficus hedges, Ficus nitida and Ficus benjamina, the standard villa boundary in Dubai, host the ficus whitefly, which drops leaves in handfuls.
- Hibiscus, Hibiscus rosa-sinensis, carries silverleaf whitefly on its soft new growth and yellows from the tip down.
- Lantana, Lantana camara, grows in almost every roundabout and villa bed and holds whitefly through the hottest months.
- Citrus trees, lemon, lime and orange, carry whitefly on the underside of young flush leaves, with sooty mould following.
- Tomatoes, aubergines and chillies in winter vegetable beds pick up whitefly from November and suffer most from the viruses it carries.
Ficus hedges are the ones that change the look of a street. A 2 m hedge can lose half its leaves within weeks of a heavy attack, and the bare stems stay bare for months.
Vegetable beds are the costliest in a different way. Silverleaf whitefly spreads tomato yellow leaf curl virus, and an infected plant stops setting fruit for the rest of the season.
Indoors, whitefly rarely troubles foliage houseplants. It turns up on a potted hibiscus or a poinsettia brought in from outside.
How to control whitefly in the garden
Control whitefly in a garden by knocking back adults with water, catching fliers on yellow sticky traps and spraying the leaf undersides with insecticidal soap or neem on a 5 to 7 day cycle for four weeks. Hedges and trees taller than 2 m need a systemic treatment instead.
Hose the undersides of the host plants hard, early in the morning. It knocks adults and honeydew off together.
Hang yellow sticky cards at leaf height, one per 2 m of hedge. They catch adults and tell you whether numbers are rising or falling from week to week.
Spray soap or neem in the evening, never under midday sun, and reach the undersides. The young can't move, so every one the spray touches dies.
For a ficus hedge the only practical fix is a systemic drench into the root zone, applied in spring before the summer peak. The chemical moves up into every leaf, and the young feeding underneath take it in.
Cut out the worst hibiscus and lantana growth before treating. A hard prune removes the young with the leaves.
How to control whitefly on indoor plants
Indoors, whitefly is controlled on the plant itself because there are few plants for it to move between. Isolate the infested pot, shower the leaves, hang a sticky card beside it and spray the undersides with insecticidal soap every 5 days for three weeks.
A plant that stays infested after three weeks is better cut back hard or replaced. Whitefly moves to other soft leaved plants in the room otherwise.
Keep new outdoor plants on a balcony for two weeks before bringing them in.
A villa with a long ficus hedge or a mature citrus is a different job. Treating the full height and length of a hedge and repeating it through the season is part of a regular garden maintenance service visit, where the gardener checks the five host plants on every round.
FAQ
Whitefly questions from villa owners tend to be about timing and about the black film left behind. The pest follows the seasons here closely, and the mould it leaves is a separate problem that sticks around after the insects have gone.
When is whitefly worst in the UAE?
Whitefly builds from March, peaks through the hot months to October, and eases between December and February. Numbers on ficus hedges climb fastest in April and May. Traps hung in March show the rise two to three weeks before the leaves start dropping.
How do you remove the black mould whitefly leaves behind?
The black film is sooty mould growing on honeydew. It washes off with warm water and a few drops of liquid soap on a sponge, or a hose on hedges. It returns while whitefly is still feeding, so treat the insects first, then clean the leaves.