What's eating my tree philodendron?

Tree philodendron (Thaumatophyllum bipinnatifidum) is vulnerable to spider mites and mealybugs when grown indoors, and to aphids and scale. Its large split leaves make infestations easy to spot but hard to treat thoroughly. Wipe down the leaves regularly, maintain humidity, and treat with neem oil or insecticidal soap at the first sign of pests.

White cottony masses in leaf axils and along petioles; honeydew deposit leading to sooty mold; yellowing and drooping leaves. Swab colonies with alcohol-soaked cotton; spray plant with neem oil solution; isolate the plant and retreat after 10 days.

Fine webbing on undersides of leaves; pale, speckled or bronzed leaf surfaces; leaf drop in severe infestations. Shower the plant to knock mites off; apply insecticidal soap or neem oil; increase ambient humidity to deter reinfestation.

Hard or waxy brown or tan bumps on stems and leaves; sticky honeydew; leaves lose vigor and may yellow. Scrape off scales manually; treat with horticultural oil spray, coating all surfaces; follow up in 2 weeks.

Clusters of soft insects on new growth; curled, distorted leaves; sticky honeydew attracting ants or sooty mold. Blast off with a strong stream of water; apply insecticidal soap spray; repeat every few days until clear.