What's eating my begonia dregei?

Begonia dregei, a caudex-forming houseplant, is most commonly troubled by mealybugs hiding in leaf axils and along stems, and by spider mites in dry indoor air. Powdery mildew can also disfigure foliage in low-airflow rooms. Inspect the caudex base regularly and maintain moderate humidity to stay ahead of problems.

White cottony clusters in leaf axils and stem joints; leaves yellow and drop Dab colonies with a cotton swab dipped in 70% isopropyl alcohol; follow with neem oil spray; isolate the plant

Fine stippling on leaves, thin webbing on undersides; foliage looks dusty and bronzed Rinse foliage with lukewarm water; apply insecticidal soap or neem oil every 5–7 days; raise humidity above 50%

White floury coating on leaf surfaces, especially in cool low-airflow spots Improve air circulation; remove affected leaves; apply dilute potassium bicarbonate or neem oil spray