Plant care guide

Spider Mites on Anthurium: Confirm, Rinse and Treat

Updated

Why does my Anthurium have spider mites?

Spider mites on an anthurium show as fine pale speckling on the leaves, tiny moving dots and pale cast skins on the leaf undersides, and fine webbing in heavy infestations. They feed by sucking out leaf cells and build up fastest on warm, dry, stressed plants.

What to do first

Confirm mites with a hand lens or the white-paper test, isolate the plant, and rinse the leaf undersides. If mites remain, use an insecticidal soap or horticultural oil labeled for indoor plants and spider mites, covering the undersides and repeating as the label directs.

Spider mites are one of the pests NC State Extension tells growers to monitor on Anthurium andraeanum and the wider Anthurium genus. UF/IFAS Extension also lists mites among the potential pests in its Anthurium fact sheet.

They are tiny arachnids, not insects. Damage on a glossy anthurium leaf usually shows before you see the mites. Confirm them first, because several other problems leave spots on anthurium leaves.

Confirm it is spider mites

Look at the leaf surface. The RHS describes glasshouse red spider mite damage as fine pale mottling on the upper leaf surface. UC IPM’s spider mite page adds that leaves can turn bronze, then yellow, and drop when numbers are high.

Check the undersides with a hand lens. The RHS says the undersides carry tiny yellowish-green mites, white cast skins and egg shells, easiest to see with a x10 lens. Despite the name, the mites are usually yellowish-green with two dark patches.

Do the white-paper test. Hold white paper under a speckled leaf and tap it. University of Minnesota Extension’s spider mite guide recommends this. Mites show as dots that start to move.

Look for webbing. Fine silk across leaves and stalks appears in heavier infestations. UC IPM notes that webbing separates spider mites from aphids and thrips on leaf undersides.

Rule out lookalikes

  • Thrips: NC State lists thrips on anthurium too. UC IPM notes that webbing is what separates spider mites from thrips and aphids on leaf undersides.
  • Mealybugs and scale: NC State lists both on anthurium, and the RHS names mealybugs as a pest that can colonise anthuriums. Use the hand lens: spider mites are the tiny dots that move.
  • Nutrient spots: UF/IFAS Extension’s interiorscape anthurium guidelines link uneven yellowish spots to manganese deficiency, with no pests present.
  • Drought stress: Minnesota Extension warns that mite damage can be confused with drought stress. Check the mix as well as the leaves.

Treat an anthurium with spider mites

  1. Isolate the plant. Move it away from other houseplants so mites cannot drift across.
  2. Water it first if the mix is dry. Minnesota Extension advises watering plants thoroughly before any spray, and UC IPM warns against spraying water-stressed plants.
  3. Rinse the leaves. A strong spray of water dislodges mites and washes off webbing, according to both UC IPM and Minnesota Extension. Aim at the undersides. Do this in a sink or shower in the morning.
  4. Let the foliage dry quickly. NC State notes that wet foliage and poor air circulation can cause leaf spots on anthurium. UF/IFAS adds that blight bacteria spread across wet leaf surfaces in its anthurium disease guide. Give the plant air and light until the leaves are dry.
  5. Spray if mites persist. Use an insecticidal soap or horticultural oil labeled for spider mites and indoor plants. Cover both leaf surfaces, especially the undersides.
  6. Test first. UC IPM advises testing a soap or oil on part of the foliage several days before a full treatment. Do not spray in heat above 32 °C (90 °F).
  7. Repeat as the label directs. Minnesota Extension notes that soaps and oils kill only the mites they touch and leave no residual protection. Eggs and missed mites survive one round.

Do not make your own soap spray. Minnesota Extension warns that homemade soap solutions can burn and damage plants.

Wear gloves. The RHS notes that anthurium sap can irritate skin.

Check whether treatment worked

Old speckles will not turn green again. Judge progress by new leaves and by the undersides. UC IPM notes that mites are sometimes gone by the time damage is noticed, and that plants often recover once mites have left.

Repeat the hand-lens and white-paper checks every few days. Fresh speckling, moving mites or new webbing mean the population is still active.

Prevent a return

  • Avoid water stress. UC IPM and the RHS both say mites build up on hot, dry, water-stressed plants.
  • Keep leaves clean. UF/IFAS Extension suggests misting anthuriums to dislodge dust, and NC State recommends wiping leaves periodically. UC IPM links dusty conditions to mite outbreaks.
  • Inspect new plants before they join your collection.
  • Watch warm, dry rooms. The RHS notes that spider mites thrive in warm, dry conditions, so check leaf undersides more often in heated rooms.

For a general mite guide covering every houseplant, see spider mites on houseplants. The anthurium hub collects our other anthurium pages.

Other anthurium problems we cover: watering frequency, overwatering, common problems, brown spots, not blooming.

References

How this guide was put together: UC IPM, University of Minnesota Extension, RHS, NC State Extension, and UF/IFAS Extension guidance.

Other Anthurium problems

Related plant care guides

Knowledge record: GR-345041