Divisi
Whitefly
Bemisia tabaci · Insect
The whitefly (Bemisia tabaci) is a tiny, sap-sucking insect no bigger than a grain of sugar. Its white, moth-like adults and flat, scale-like young crowd the underside of leaves, where they drain the plant's sap, coat it in sticky honeydew that blackens with sooty mould, and — most dangerous of all — carry plant viruses such as cassava mosaic and tomato leaf curl from one plant to the next.
Why it matters
A whitefly attack can cost you more than half your crop — up to 60%. But the worst harm isn't the sap they drink: whitefly is a vector — a carrier that moves plant viruses (like cassava mosaic and tomato leaf curl) from sick plants into healthy ones. Once a plant catches the virus there is no cure — you can kill every last fly and the sick plants stay sick and stunted. And whitefly is stubborn: it breeds very fast in warm, dry weather, hides under the leaves where sprays miss it, and quickly stops dying to a spray you lean on too often. That is why you must act early, while numbers are still low — before the virus gets a foothold in your field.
When to act
Clouds of tiny white flies rise when plants are disturbed, or several adults or nymphs per leaf on young plants; act early where the crop is virus-susceptible.
This guidance is general, compiled from published agronomic references including FAO and CABI. Thresholds and timing shift with your crop, your variety and the season.
In much of the region a spray is simply called mushonga — medicine. But a chemical group you cannot name is one you cannot rotate, and a product you did not write down has no pre-harvest interval you can observe. Mushonga, and other farming words →
The full whitefly field guide
- Identify it
- Scout for it
- Control it
16 field-guide sections in the app
The full guide to whitefly — every symptom to check, how and when to walk your field looking for it, and the controls that actually work, ranked. Built into your crop plan, so you are told to look before it costs you a harvest.
Crops it affects
Frequently asked questions
How do I identify whitefly?
The first thing you notice is the mess they leave. Leaves turn sticky and shiny, as if sprinkled with sugar-water — that is honeydew, the sweet waste the flies drip. A black, sooty mould then grows on the stickiness, blackening leaves and fruit, while the leaves themselves yellow, curl and wilt and the plant looks tired and stunted.
When should I take action against whitefly?
Clouds of tiny white flies rise when plants are disturbed, or several adults or nymphs per leaf on young plants; act early where the crop is virus-susceptible.
How do I control whitefly?
Start clean — this is your strongest defence. Plant only clean, virus-free seedlings and cuttings: for cassava, take cuttings only from healthy-looking mother plants; for tomato and beans use fresh, healthy seedlings. One infected plant carries the virus straight into your field, so never plant material taken from sick-looking plants.
Which crops does whitefly affect?
Among the crops covered here: Cabbage, Cassava, Cotton, Sweet potato, Tomato.
Catch it before it costs you a harvest
Divisi builds scouting into your crop plan — it tells you when to walk your field, what to look for at that stage, and what to do when you find it. Free for farmers, works offline.
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