Alocasia: silvery or mottled leaf surface

What it is likely to be on alocasia

1. Red spider mite

   Candidate 1very common on this plant

   ·source

   Sourced guidancehigh confidence

   • Royal Horticultural Society: Glasshouse red spider mite
   • Home and Garden Information Center — Clemson Cooperative Extension: Spider mites on houseplants

   Checked 2026-08-13

   A sap-feeding mite barely visible to the naked eye, thriving in the hot dry air of a heated room or a greenhouse. The first sign is a fine pale stippling on the leaves; by the time webbing is obvious between the leaves and stems the population is large.

   Points towards it

   • · fine webbing between the leaflets and at the leaf axils is spider mite and is produced by nothing else in this differential
   • · the feeding empties individual cells, producing a fine pale stipple that reads as a silvered or dusty surface
   • · hot dry indoor air in winter is where populations build fastest
   • · a plant kept dry at the root is more heavily attacked than one kept moist

   Argues against it

   • · honeydew is sugar passed through an insect gut and mites do not produce it — a sticky plant has a sap-feeding insect instead — this rules it out entirely.

   Check this next

   Turn a mottled leaf over and hold it to the light, then look along the leaf axils. Spider mite lives on the underside: a fine pale stipple from above, minute moving specks below, and gossamer webbing where leaflets meet the stem. If the plant is also sticky to the touch, stop — that is a sap-feeding insect, and mites never leave honeydew.

   What to do now

   Raise the humidity and wash the plant down: a shower or a firm spray, undersides included, repeated weekly for a month, removes most of a population and keeps it down — mites do badly in moving humid air. Isolate the plant from its neighbours while you do it, because they spread by contact, and cut off leaves that are more than half stippled since they will not recover.

   ·source

   Sourced guidancehigh confidence

   • Royal Horticultural Society: Glasshouse red spider mite — control

   Checked 2026-08-13

2. Thrips

   Candidate 2common on this plant

   ·source

   Sourced guidancemoderate confidence

   • Royal Horticultural Society: Thrips
   • UC Statewide Integrated Pest Management Program — University of California Agriculture and Natural Resources: Thrips — management

   Checked 2026-08-13

   Slender insects barely a millimetre long that rasp the leaf surface and drink what leaks out. The feeding empties the cells, so the leaf takes on a silvery or pewter sheen quite unlike ordinary yellowing — and the tiny black specks of frass scattered over that silvering are what separate thrips from spider mite.

   Points towards it

   • · tiny black varnish-like specks scattered across the silvered surface are thrips droppings, and spider mite leaves nothing of the kind
   • · thrips feed in the unfurling leaf at the growing point, so the newest growth is damaged and often distorted as it opens
   • · slender dark insects a millimetre or two long, running rather than flying when disturbed, are the animal itself
   • · thrips breed continuously in warm indoor conditions

   Argues against it

   • · fine webbing across the leaf and in the axils is spider mite, which silvers a leaf the same way and leaves no black specks — this rules it out entirely.
   • · a close inspection of the new growth that found neither insects nor frass argues against an active thrips population

   Check this next

   Take the newest, most recently unfurled leaf to a window and look at both surfaces closely, ideally with a hand lens. Thrips damage is a silvery or pewter sheen where the cells have been emptied, and scattered over it are minute black specks of frass that look like flecks of varnish and will not brush off easily — that frass is the diagnosis. Then shake the leaf over a sheet of white paper: thrips drop off and run. If instead you find fine webbing in the leaf axils and no black specks, it is spider mite, which needs the same isolation and a different expectation of how fast it moves.

   What to do now

   Isolate the plant straight away — thrips fly and will move to everything nearby. Wipe both surfaces of every leaf with a damp cloth to remove the adults, the larvae and the frass, paying particular attention to the newest growth and the furled centre where they feed, and cut off any leaf that is badly scarred and distorted. Repeat weekly for at least a month, because eggs are laid inside the leaf tissue and hatch in waves. Yellow or blue sticky traps hung at the plant will show whether adults are still active. Damaged leaves will not recover their colour; judge success on whether the next leaf to open is clean.

   ·source

   Sourced guidancemoderate confidence

   • Royal Horticultural Society: Thrips — control

   Checked 2026-08-13

Narrow it down

This page lists everything at once, which is the right shape for reading and the wrong shape for deciding. The interactive tool asks one question at a time, starting with whichever would separate these causes fastest, and stops as soon as further answers would not help.

Opens with the plant and the symptom already set. Nothing you answer is stored or sent anywhere — the answers live in the address bar and nowhere else.

What this does not cover

These are the causes GrowingHQ holds rules for on alocasia — not every cause there is. Where several problems look alike, the honest answer is often that they cannot be told apart by eye, and a page that named one would be guessing. If none of the above fits, the general silvery or mottled leaf surface page lists causes across all plants, and the Alocasia profile lists the problems it is prone to.