What's eating my begonia goegoensis?

Begonia goegoensis, a rhizomatous species from Sumatra grown indoors, is most vulnerable to mealybugs and fungus gnats. Its shallow rhizome and love of humidity create ideal mealybug habitat, while consistently moist potting mix attracts fungus gnats. Good airflow and careful watering are the first line of defence.

Waxy white fluff at leaf bases and rhizome joints; honeydew leads to sooty mould and weakened growth. Apply 70% isopropyl alcohol to visible clusters with a cotton swab; follow up with neem oil drench and foliar spray for four weeks.

Larvae feed on fine roots in the potting mix, causing wilting and poor growth; adults are a nuisance around plants. Allow the top 2–3 cm of compost to dry before watering; apply a Bacillus thuringiensis israelensis (Bti) soil drench; use yellow sticky traps to catch adults.

Pale stippling on the distinctive patterned leaves; fine webbing on undersides reduces ornamental value quickly. Increase humidity, wipe leaves with a damp cloth, then spray with insecticidal soap or diluted neem oil every five to seven days.