Pest identification
What's eating my haricot vert?
Black bean aphid (Aphis fabae)
Signs: Dense black colonies on shoot tips and undersides of leaves; distortion and sooty mold (UK dominant)
Control: Pinch out heavily infested tips, spray with insecticidal soap or soft soap, encourage lacewings and ladybirds
Mexican bean beetle (Epilachna varivestis)
Signs: Skeletonized leaves from below; lacy yellow appearance (US dominant)
Control: Hand-pick egg clusters, apply spinosad or neem oil to leaf undersides
Slugs & snails
Signs: Ragged holes in seedling leaves; silvery slime trails on soil and foliage
Control: Iron phosphate pellets, beer traps, copper tape, hand-pick after dark
Spider mites
Signs: Fine yellow stippling and webbing, particularly in hot dry summers or polytunnel growing
Control: Maintain moisture, mist foliage, apply neem oil or release Phytoseiulus persimilis predatory mites
Keep haricot vert pest-free
Healthy plants resist pests best. Get the basics right:
Haricot Vert pests — FAQ
What is eating my haricot vert?
Haricot vert (French filet beans) attract aphids, slugs on seedlings, and spider mites in hot weather. In the UK and Europe, black bean aphid (Aphis fabae) is a major pest colonizing shoot tips. Mexican bean beetle is the main US threat. Slugs damage young plants at night. Black bean aphid is the leading UK pest.
How do I get rid of black bean aphid (aphis fabae) on haricot vert?
Dense black colonies on shoot tips and undersides of leaves; distortion and sooty mold (UK dominant) Pinch out heavily infested tips, spray with insecticidal soap or soft soap, encourage lacewings and ladybirds
How do I get rid of mexican bean beetle (epilachna varivestis) on haricot vert?
Skeletonized leaves from below; lacy yellow appearance (US dominant) Hand-pick egg clusters, apply spinosad or neem oil to leaf undersides
How do I get rid of slugs & snails on haricot vert?
Ragged holes in seedling leaves; silvery slime trails on soil and foliage Iron phosphate pellets, beer traps, copper tape, hand-pick after dark
How do I get rid of spider mites on haricot vert?
Fine yellow stippling and webbing, particularly in hot dry summers or polytunnel growing Maintain moisture, mist foliage, apply neem oil or release Phytoseiulus persimilis predatory mites