• Adult flea beetles cause distinctive ‘pitting’ in leaf surfaces. This type of damage is easily recognizable.
  • Beetles are small (most <1/4″) and have enlarged femurs on their back legs. This allows them to jump very far, hence the common name. The ‘thickened thighs’ can be used as an identification tool.
  • Some of the common flea beetles we have here in the PNW are

Phyllotreta cruciferae, crucifer flea beetle : metallic blue-green to black

Phlyllotreta albionica, cabbage flea beetle: dark with a bronze sheen

Phyllotreta striolata, striped flea beetle: black with wide, wavy yellow stripes on wing covers

  • The above species feed on brassica crops and cruciferous weedy hosts like yellow rocket and wild mustard.
  • Activity increases with warming temperatures, and invasion into fields can be rapid.
  • Newly seeded crops are particularly vulnerable, damage to cotyledons can cause uneven stands or crop loss.
  • Transplants with 3+ leaves can withstand more damage but should still be monitored closely.
  • Treatment on cole crops is recommended when 10-20% of a stand shows feeding damage.
  • Spot or border treatments can be effective. Consult the PNW Insect Management Handbook for labeled products.