What's eating my begonia × erythrophylla?

Begonia × erythrophylla, the beefsteak begonia, is a tough indoor houseplant that most commonly encounters mealybugs sheltering at rhizome nodes and mite infestations in dry, warm rooms. Its thick, waxy leaves resist some damage but mask early mealybug colonies — inspect where leaves meet the rhizome at every watering.

Cottony white clusters at rhizome joints and the base of petioles; slow growth and sticky leaves. Remove with an alcohol-dipped cotton swab; treat with neem oil spray on all surfaces weekly for a month.

Fine pale stippling on leaf surface; webbing in joints during dry winter heating season. Wipe leaf surfaces with a damp cloth; spray neem oil or insecticidal soap and repeat every 5 days.

Larvae damage roots in overly moist compost; adults are a nuisance flying around the plant. Allow the top inch of compost to dry between waterings; apply sticky yellow traps and Bti drench.