Divisi
Amaranth leaf webber
Spoladea recurvalis · Insect
Photo: Vengolis · CC BY-SA 4.0
The amaranth leaf webber (Spoladea recurvalis), also called the Hawaiian beet webworm, is a small night-flying moth whose translucent green caterpillars spin silk to fold and tie amaranth leaves together, then feed hidden inside the shelter. It attacks amaranth and other leafy greens such as spinach and beetroot tops, skeletonising the leaves and packing the folds with droppings. In warm, humid weather one generation follows another quickly, so numbers explode on continuous leafy plantings.
Vengolis · CC BY-SA 4.0 
Forest and Kim Starr · CC BY 3.0 us
Why it matters
Amaranth is grown and sold for its leaves — so this pest hits you exactly where it hurts, on the very part you take to market. A heavy attack skeletonises and webs up your plants and can cost you up to 60% of the crop (more than half), and even light webbing and droppings make leaves unsellable. It is hard to stop once it settles in, because the caterpillars hide inside the folded, webbed leaves where sprays cannot reach, and in warm weather one generation follows another fast. Catching it early, while the caterpillars are small and out in the open, is everything.
When to act
Act when webbed leaves and caterpillars are found on about 1 in 5 plants, or earlier on a young leafy crop being sold whole.
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 amaranth leaf webber field guide
- Identify it
- Scout for it
- Control it
15 field-guide sections in the app
The full guide to amaranth leaf webber — 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 amaranth leaf webber?
The damage (what you see first): young leaves and growing tips folded over and tied together with fine silk webbing, like a little tent or parcel. Open one and the leaf inside is eaten down to a thin, see-through skin — "windowed" and skeletonised (only the veins left) — and packed with green-black droppings (frass). Under heavy attack whole plants look stripped, ragged and dirty with webbing.
When should I take action against amaranth leaf webber?
Act when webbed leaves and caterpillars are found on about 1 in 5 plants, or earlier on a young leafy crop being sold whole.
How do I control amaranth leaf webber?
Prevent it — break the food chain: don't plant amaranth back-to-back on the same ground. The caterpillars need a constant supply of tender leaves, so rotate your leafy plots and leave a gap in time that starves each new generation. After every harvest, pull out and destroy old crop residues and weeds — wild amaranth and pigweed shelter the pest between crops.
Which crops does amaranth leaf webber affect?
Among the crops covered here: Amaranth, Beetroot.
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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