What's eating my allium 'purple sensation'?

Alliums are largely pest-resistant thanks to their pungent chemistry, but allium leaf miner and onion thrips are the main insect threats. Slugs can damage emerging foliage in spring, and narcissus bulb fly occasionally attacks the bulbs. Deer and rabbits typically avoid them.

White stippling trails along leaves followed by tunnelling maggots in stems and bulbs; plants collapse. Cover with fine insect-proof mesh (crop fleece) during adult flight periods (spring and autumn). Remove and destroy affected plants promptly.

Silver-white streaking and distortion on leaves; heavy infestations stunt growth. Remove badly affected foliage; apply insecticidal soap or spinosad spray; avoid overhead watering which worsens conditions.

Holes and ragged edges on fresh spring foliage, especially in wet seasons. Iron phosphate pellets around emerging shoots; hand-pick in the evening; improve drainage to reduce slug habitat.