Pest identification
What's eating my scarlet runner bean?
Black bean aphid (Aphis fabae)
Signs: Dense black colonies at shoot tips and growing points; leaves distort and plants weaken
Control: Pinch and bin infested tips, spray with insecticidal soap, attract or release hoverflies and ladybirds
Mexican bean beetle (Epilachna varivestis)
Signs: Skeletonized, lacy leaves as larvae graze the underside (US gardens)
Control: Scout weekly, hand-pick, apply neem oil or spinosad to undersides of leaves
Slugs & snails
Signs: Seedlings eaten at ground level or leaves holed overnight
Control: Iron phosphate pellets, copper barrier tape, beer traps, hand-pick at dusk
Birds (pigeons, jays)
Signs: Emerging seedlings pulled up and seeds eaten; fresh soil disturbed
Control: Cover seeds and seedlings with fleece or wire netting until first true leaves fully open
Keep scarlet runner bean pest-free
Healthy plants resist pests best. Get the basics right:
Scarlet Runner Bean pests — FAQ
What is eating my scarlet runner bean?
Scarlet runner beans are dogged by black bean aphid (the top UK pest), Mexican bean beetle in the US, slugs on seedlings, and birds that pull up emerging seeds. Hummingbirds visit the flowers but don't damage plants. Aphids are the most consistently troublesome pest on both sides of the Atlantic.
How do I get rid of black bean aphid (aphis fabae) on scarlet runner bean?
Dense black colonies at shoot tips and growing points; leaves distort and plants weaken Pinch and bin infested tips, spray with insecticidal soap, attract or release hoverflies and ladybirds
How do I get rid of mexican bean beetle (epilachna varivestis) on scarlet runner bean?
Skeletonized, lacy leaves as larvae graze the underside (US gardens) Scout weekly, hand-pick, apply neem oil or spinosad to undersides of leaves
How do I get rid of slugs & snails on scarlet runner bean?
Seedlings eaten at ground level or leaves holed overnight Iron phosphate pellets, copper barrier tape, beer traps, hand-pick at dusk
How do I get rid of birds (pigeons, jays) on scarlet runner bean?
Emerging seedlings pulled up and seeds eaten; fresh soil disturbed Cover seeds and seedlings with fleece or wire netting until first true leaves fully open