What's eating my begonia nelumbiifolia?

Begonia nelumbiifolia (lily-pad begonia) is a large-leaved houseplant begonia prone to mealybugs hiding along petioles and undersides, thrips rasping the broad leaf surface, and fungus gnats breeding in its consistently moist potting mix. Its large leaves make thrips damage very visible. Mealybugs are the most persistent indoor threat.

Cottony white clusters at leaf-stem junctions and petiole bases; weakened plant; leaves yellow and drop Remove colonies with an alcohol-dipped swab; treat with insecticidal soap or neem oil spray; repeat every seven days; isolate affected plant

Silver-streaked or bronzed patches on large leaf surfaces; tiny dark frass spots; distorted new leaves Introduce Amblyseius cucumeris predatory mites; apply spinosad-based insecticide; remove heavily damaged leaves and sticky trap adults

Adult flies hovering around soil; larvae damage roots and emerging petioles in waterlogged compost Let the top inch of compost dry before watering; apply Steinernema feltiae nematodes; use yellow sticky traps to monitor adults