What's eating my netted iris?

Netted Iris (Iris reticulata) is a small bulbous iris prone to ink disease (a fungal rot causing black staining of bulbs) and aphid attack on emerging shoots. Vine weevil larvae can eat bulbs in containers. Slugs may nibble early spring growth. Ink disease is the most feared threat to this species.

Black crusty patches on bulb skin; leaves turn yellow and die back early; rotted black tissue inside the bulb Dig and destroy infected bulbs immediately; do not replant irises in the same spot for several years; improve drainage; avoid wounding bulbs

Clusters of greenish or black aphids on emerging shoots and flower stems; sticky honeydew and weakened growth Spray with insecticidal soap; hand-crush small colonies; encourage aphid predators

Grubs eat bulbs from below causing sudden plant collapse; adults notch leaf margins at night Apply vine weevil nematodes (Steinernema kraussei) to compost in autumn; use neonicotinoid-free biological controls in containers