What's eating my poinsettia?

Poinsettias are most commonly attacked by whitefly indoors — the primary commercial pest — along with mealybugs, spider mites, and fungus gnats in soggy soil. Sticky yellow traps catch adults early; neem oil or insecticidal soap handles mealybugs and mites. Good air circulation and avoiding overwatering prevent most problems.

Clouds of tiny white insects fly up when the plant is disturbed; leaves turn yellow and drop; sticky honeydew coats foliage. Hang yellow sticky traps; spray leaves (especially undersides) with insecticidal soap or neem oil every 5–7 days for 3–4 cycles.

White cottony clusters in leaf axils and where bracts meet stems; leaves yellow and growth stalls. Dab individual colonies with a cotton swab dipped in 70% isopropyl alcohol; follow with neem oil spray to catch crawlers.

Fine bronze stippling on leaves; fine webbing on undersides of leaves in heavy infestations, especially in hot, dry indoor air. Raise humidity, mist undersides of leaves, and apply insecticidal soap or neem oil; repeat weekly for at least 3 weeks.

Larvae in overwatered soil chew fine roots, causing sudden wilting; adults are harmless but a nuisance. Allow the top 2 inches of compost to dry between waterings; use yellow sticky traps for adults; apply Bacillus thuringiensis israelensis (Bti) drench for larvae.