Divisi
Fruit flies
Bactrocera dorsalis · Insect
Fruit flies (Bactrocera dorsalis, the Oriental fruit fly) are small, yellow-shouldered flies whose females "sting" ripening fruit — mango, guava, papaya, citrus, avocado and more — jabbing their eggs in just under the skin. The white maggots (fly grubs) that hatch tunnel and feed hidden inside, rotting the flesh so the fruit ripens unevenly and drops early. The full-grown maggots then crawl out into the soil to turn into new flies, so where warm, humid weather keeps some host fruit ripening almost all year, generations overlap and numbers build up fast.
Kembangraps · CC BY-SA 4.0 
Florida Department of Agriculture · Public domain
Why it matters
Fruit flies can rot up to 6 in every 10 fruit on a tree — mango, guava, papaya, orange, avocado and more — turning a good harvest into piles of maggoty, unsellable windfalls. The female stings the ripening skin and lays her eggs just beneath it, so the damage stays hidden inside: by the time you notice the soft, sunken rotten spot, the maggots are already tunnelling and no spray can reach them. Those maggots then drop with the fruit and burrow into the soil to become the next wave of flies, so once they settle into your orchard they keep coming back — which is why catching them early and destroying every fallen fruit matters so much.
When to act
flies caught rising in pheromone/food-bait traps as fruit begins to mature, or first stung fruit with oozing punctures
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 fruit flies field guide
- Identify it
- Scout for it
- Control it
12 field-guide sections in the app
The full guide to fruit flies — 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 fruit flies?
The damage you see first: tiny sting punctures on the skin of ripening fruit, each with a bead of clear sap or gum oozing out that later darkens into a soft, sunken brown spot. The flesh beneath rots, the fruit ripens unevenly and drops early, and when you cut a suspect fruit open you find small white maggots tunnelling in the pulp.
When should I take action against fruit flies?
flies caught rising in pheromone/food-bait traps as fruit begins to mature, or first stung fruit with oozing punctures
How do I control fruit flies?
Prevent it — orchard sanitation is your strongest everyday tool: twice a week, gather up every fallen and stung fruit, from the ground and off the tree, and destroy it — bury it at least knee-deep (about 50 cm) so the flies inside cannot dig back out, or seal it in a black plastic bag left in the sun for a week, or boil or burn it. This starves the next generation, because the maggots crawl out of dropped fruit into the soil to become new flies. Also bag your high-value fruit (mango, guava) in paper or net sleeves once it sets, and pick at the right maturity instead of leaving ripe fruit hanging as a breeding site. Do this together with your neighbours — flies cross fences.
Which crops does fruit flies affect?
Among the crops covered here: Avocado, Cucumber, Guava, Hot pepper, Mandarin / tangerine, Mango, Papaya, Sweet orange.
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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