What's eating my sempervivum 'black'?

Sempervivum 'Black' is one of the hardiest houseleeks and seldom heavily pestered, but mealybugs can shelter inside rosette leaves and vine weevil grubs attack roots in containers. Root mealybugs occasionally infest potted plants. Its compact succulent rosette resists most insects. Mealybugs are the single most common nuisance.

Fluffy white cottony clusters at leaf axils; honeydew residue and eventual rosette collapse if untreated. Apply isopropyl alcohol on a cotton swab; spray with insecticidal soap; repeat weekly for three weeks.

Root grubs chew roots causing sudden rosette death; adults may notch leaf edges if moved outdoors. Drench container soil with Steinernema kraussei nematodes in late summer; physically remove grubs when repotting.

Powdery white coating on roots; plant wilts and growth stalls despite regular watering. Bare-root the plant, soak roots briefly in dilute neem solution, let dry, repot in sterile gritty compost.