Divisi
Cassava green mite
Mononychellus tanajoa · Mite
Photo: David Monniaux · CC BY-SA 3.0
Cassava green mite (Mononychellus tanajoa) is a spider mite so small it looks like green dust, and cassava is its only host. It gathers on the underside of the youngest top leaves and in the growing tips, sucking the sap and leaving a fine yellow-green speckling. It builds up in the hot, dry season and in long droughts, then collapses when the rains return. Brought to Africa from South America, it is now found right across the cassava belt — but a tiny predatory mite, introduced to hunt it, keeps it in check in many areas.
EdwinAlden.1995 · CC BY-SA 4.0 
Abike25 · CC BY 4.0
Why it matters
A bad dry-season attack can cost you up to half your root harvest — the mites feed on the growing tips, so the plant stops pushing out new leaves and the roots below the ground stay small. The mites are almost too small to see and hide under the youngest top leaves and deep in the shoot tips, so by the time the tips look burnt and stand up bare like a candlestick, much of the damage is already done. There is no quick spray that fixes this well — once the mite is established you are managing it, not curing it — so the real win is preventing the build-up and letting its natural enemy do the work.
When to act
Green speckling and stunting on young top leaves during the dry season; treat when growing tips are heavily colonised.
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 cassava green mite field guide
- Identify it
- Scout for it
- Control it
13 field-guide sections in the app
The full guide to cassava green mite — 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 cassava green mite?
The damage first: look at the youngest leaves at the very top of the plant. Fine yellow-green speckles appear first — as if someone flicked pale dust across the leaf — then those top leaves turn mottled, twisted and small. In a bad, long dry spell the growing tips die back and the plant is left with a bare, stalky top — a 'candlestick' look — and it stops growing taller.
When should I take action against cassava green mite?
Green speckling and stunting on young top leaves during the dry season; treat when growing tips are heavily colonised.
How do I control cassava green mite?
Prevent it — start clean and plant early: take your cuttings only from healthy, mite-free plants, and never carry cuttings from an infested field into a clean one — that is how the mite travels. Plant early, at the start of the rains, so the crop is strong and well-established before the dry season arrives and the mite builds up. Keep plants vigorous — good spacing, weeded, not drought-starved — because a strong plant shrugs off far more mite feeding than a stressed one.
Which crops does cassava green mite affect?
Among the crops covered here: Cassava.
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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