Begonia foliosa · Shrub
Vine weevil: Apply biological control products containing nematodes to the compost in late summer.
Powdery mildew: Improve air circulation and treat with a suitable fungicide or potassium bicarbonate spray.
Mealybugs: Wipe off infestations with a damp cloth dipped in methylated spirit or use insecticidal soap.
Red spider mites: Increase humidity around the plant and spray with a horticultural oil or miticide.
Grey mould: Remove affected parts immediately and ensure good ventilation to reduce humidity.