What's eating my pelargonium peltatum 'tomcat'?

Pelargonium peltatum 'Tomcat' (ivy-leaved geranium) is most threatened by caterpillars of the geranium bronze butterfly in Europe and by aphids. Vine weevil attacks container-grown plants. Whitefly can build up in sheltered patio spots. Slugs occasionally damage stems at soil level in damp conditions.

Holes bored into stems and flower buds; frass and wilting of shoots; common in Europe and California Remove affected shoots promptly; apply Bacillus thuringiensis (Bt) spray; inspect buds weekly and destroy egg clusters

Distorted young shoots and flower buds; sticky honeydew and sooty mold on leaves Blast off with a strong water jet; apply insecticidal soap or neem oil spray; encourage aphid predators such as ladybugs

Adults notch leaf margins; grubs eat roots leading to sudden wilting and collapse in late summer Apply Steinernema kraussei nematodes to compost in late summer; use vine weevil-specific compost treatments for container plantings

Clouds of tiny white insects fly up when foliage is disturbed; yellowing leaves and sticky honeydew Use yellow sticky traps near plants; apply insecticidal soap or pyrethrin spray; introduce Encarsia formosa in glasshouses