Divisi
Thrips
Thrips tabaci · Insect
Photo: Carlos Patricio Illescas Riquelme (iNaturalist) · CC BY-SA 4.0
Thrips are minute, slender insects — most less than 2 mm long — that rasp open the surface of leaves, flowers and fruit and suck out the sap, leaving a tell-tale silvery scarring flecked with tiny black droppings. They breed explosively in hot, dry weather, throwing one overlapping generation after another, and hide deep in leaf folds, onion sheaths and flowers where sprays struggle to reach. Their worst harm is not the feeding itself but the plant viruses (such as tomato spotted wilt) that several thrips carry and inject as they feed — damage that no chemical can undo.
Jesse Rorabaugh (iNaturalist) · CC0 
Metin GÜLEŞCİ · CC BY 4.0
Why it matters
Thrips are almost too small to see, yet they can strip away up to 60% of your harvest — over half the crop. A little of that is the silvery scarring they rasp into leaves, flowers and fruit; most of it is the viruses they inject as they feed (like tomato spotted wilt), and no spray can cure a plant once it is infected. They explode in numbers in hot, dry weather, hiding deep in leaf folds, onion sheaths and flowers where sprays never reach, and they grow resistant to chemicals fast. That is why, once they are established, they are so hard to beat — and why keeping them out and catching them early matters far more than spraying late.
When to act
On onion treat at roughly one thrips per leaf on average during bulbing; on other crops act when silvering spreads or when thrips are found in flowers of virus-susceptible crops such as tomato and pepper.
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 thrips field guide
- Identify it
- Scout for it
- Control it
19 field-guide sections in the app
The full guide to thrips — 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 thrips?
The damage first: look for silvery, whitish streaks and patches on the leaves, as if the green has been scraped away and the surface has turned to tin foil. Scattered over that silvering are tiny black specks — the thrips' droppings — and those specks are the tell that a living insect, not the sun or wind, did the damage.
When should I take action against thrips?
On onion treat at roughly one thrips per leaf on average during bulbing; on other crops act when silvering spreads or when thrips are found in flowers of virus-susceptible crops such as tomato and pepper.
How do I control thrips?
Prevent it — start clean: plant only clean, thrips-free seedlings, and never carry in infested transplants. Walk the crop and rogue — that means pull out and destroy — any plant showing virus symptoms (ringspots, wilting, twisted growth) early, before thrips carry that virus on to healthy plants.
Which crops does thrips affect?
Among the crops covered here: Cabbage, Common bean, Cotton, Onion, 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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