Whitefly
Tiny white sap-suckers that cloud up when the crop is disturbed — and spread the leaf-curl and yellow-mosaic viruses that do the real damage.
- Pest type
- Sap-sucking insect
- Attacks
- Leaf undersides
- Worst in
- Warm, dry weather
- Main risk
- Leaf-curl / yellow-mosaic virus
Overview
Whiteflies are minute (1–2 mm) white, moth-like insects that sit on the underside of leaves and fly up in a cloud when the plant is shaken. Both the adults and their flat, scale-like young suck sap, weakening the plant and coating it in honeydew and sooty mould.
But whitefly is feared mainly as a virus carrier. Bemisia tabaci transmits cotton leaf-curl virus, tomato and chilli leaf-curl, and the yellow-mosaic viruses of moong, urad and soybean — diseases with no cure once a plant is infected. In those crops the whole point of whitefly control is to stop the virus, which means acting before populations build, not after the damage shows.
How to identify it
- Tiny white insects on the underside of leaves that fly up in a small white cloud when you brush or shake the plant.
- Flat, oval, scale-like immature stages fixed to the leaf underside, often with sticky honeydew and black sooty mould.
- In virus-hit crops, look for the disease signs too — upward-curling, thickened, leathery leaves (leaf curl) or bright yellow mosaic patterns.
- Yellow sticky traps quickly confirm and measure a whitefly population.
The damage it does
- Direct feeding yellows and weakens leaves and, in heavy numbers, dries them; honeydew and sooty mould blacken the canopy.
- Transmission of leaf-curl virus (cotton, tomato, chilli) — stunted plants with curled, cupped leaves and little or no yield.
- Transmission of yellow-mosaic virus (moong, urad, soybean) — bright yellow-and-green mottled leaves and heavy pod loss.
- Because the viruses are incurable, even a modest whitefly population can cause a total loss through disease.
When to act
- Hang yellow sticky traps and scout leaf undersides twice a week from early growth — in virus-prone crops, act on low numbers, not high ones.
- Whitefly builds fastest in hot, dry spells and on lush, over-fertilised crops; watch these conditions especially.
- The goal in cotton, tomato, chilli and pulses is virus prevention, so early suppression and rogueing infected plants matter more than waiting for a feeding threshold.
Organic & cultural control
- Rogue out and destroy the first virus-infected plants so they cannot be a source for whitefly to spread from.
- Use yellow sticky traps to trap adults, and spray neem oil / NSKE 5%, which deters egg-laying and is soft on natural enemies (Encarsia parasitoids, ladybird beetles).
- Choose tolerant/resistant varieties where available (many cotton and mungbean varieties are bred for leaf-curl / YMV tolerance) and avoid excess nitrogen.
- Keep the field and bunds free of virus-host weeds, and avoid staggered/overlapping sowing that gives whitefly a continuous green bridge.
Chemical control
- Whitefly develops resistance fast — rotate insecticide groups and never spray the same one repeatedly.
- CIB&RC-registered options include diafenthiuron 50% WP, flonicamid 50% WG, pyriproxyfen 10% EC (an insect growth regulator for the young stages) and spiromesifen 22.9% SC — pick one registered for your crop.
- Direct the spray to the underside of leaves where whitefly lives, and observe the label pre-harvest interval on vegetables.
- Confirm the current recommendation for your crop and area with your local KVK, especially in cotton, where insecticide rotation is critical to slowing resistance.
Crops most at risk
Where this problem is called out in our crop guides — open a crop for the full package of practices.
Frequently asked questions
A cloud of tiny white insects flies up when I disturb my plants. What are they?
Those are whiteflies — minute white sap-suckers that rest on leaf undersides and fly up when disturbed. Beyond weakening the plant and coating it in sticky honeydew, they spread leaf-curl and yellow-mosaic viruses, which is the bigger threat in cotton, tomato, chilli and pulses.
My plants have curled, cupped leaves — is that the whitefly feeding?
More likely it is a virus the whitefly carried. Leaf-curl and yellow-mosaic viruses cause the curling, cupping and mottling, and they cannot be cured once the plant is infected. That is why whitefly control is really virus prevention: act early, rogue out infected plants, and use tolerant varieties.
Why does the same spray stop working on whitefly?
Whitefly develops insecticide resistance very quickly, so repeating one product soon makes it useless. Rotate between different insecticide groups, lean on neem, sticky traps and natural enemies, and target the leaf undersides. In cotton especially, disciplined rotation is what keeps any chemical working.
Symptoms and control measures follow ICAR, KVK and state agricultural-university package-of-practices; any named chemical is a registered use. Always read the product label and confirm the dose for your crop and zone. editorial policy.