Corn flea beetle identification & organic control
Chaetocnema pulicaria
How to identify corn flea beetle
A tiny, shiny black beetle that jumps like other flea beetles but is notable for spreading Stewart's bacterial wilt in sweet corn as it feeds, a disease that can kill seedlings outright.
Crops attacked by corn flea beetle
Sweet corn.
Scrapes narrow feeding scars in leaves; the bigger threat is the Stewart's wilt bacteria it can carry from plant to plant, which causes wilting streaks and can kill young corn.
Life cycle
- Overwintering adult (Winter (in grass, debris)) — Survival tied to winter temperature; mild winters mean more beetles.
- Adults emerge (Spring) — Feed on emerging corn, potentially spreading Stewart's wilt.
- Larva (Summer) — Feeds on grass roots; minor direct damage.
- New generation adults (Late summer) — Continue feeding and disease spread into fall.
Natural, organic corn flea beetle control
- 1. Grow resistant sweet corn varieties · low effort
Many modern sweet corn varieties are bred for Stewart's wilt resistance; check seed catalog descriptions.
When: At variety selection
- 2. Row cover seedlings · medium effort
Protects the most vulnerable early stage from beetle feeding and disease transmission.
When: At emergence
Fastest-fix products
- Row cover for seedlings — Reduces both feeding and disease transmission during the critical early stage. · Garden centers, Amazon
Prevention
- Choose Stewart's wilt-resistant sweet corn varieties, especially after a mild winter.
- Remove volunteer corn and grassy weeds that host overwintering beetles.