Chard, Swiss-Cucumber beetle

Western spotted cucumber beetle (Diabrotica undecimpunctata)
Western striped cucumber beetle (Acalymma trivittatum)

Pest description, crop damage and life history


Pest monitoring Specific treatment thresholds have not been established for foliage feeding in Oregon. In Virginia, the following recommendations are made: To prevent cucumber beetle damage to seedlings, treat when one beetle per 10 feet of row is found.

Be aware of surrounding fields. As grass fields dry down prior to harvest, and when harvested vegetable crops are disked into the soil, sudden surges in beetle pressure occur as beetles migrate in from other areas.

Management-cultural control

In most years, low ebbs occur in the aboveground adult beetle populations after egg laying and prior to the emergence of the summer generation. Sometimes, the timing of a crop planting can be delayed until after beetles have dispersed and deposited most of their eggs. Trap and spray crops sometimes can be used to draw beetles away from the main crop or intercept incoming beetles at the edge of the field. Trap cropping is an unproven control method in Oregon.

Management-chemical control: HOME USE

  • acetamiprid
  • azadirachtin (neem oil)-Some formulations are OMRI-listed for organic use.
  • carbaryl
  • cyfluthrin
  • imidacloprid
  • malathion
  • permethrin
  • pyrethrins-Some formulations are OMRI-listed for organic use.
  • zeta-cypermethrin

Management-chemical control: COMMERCIAL USE

  • alpha-cypermethrin (Fastac EC) at 0.014 to 0.025 lb ai/a. PHI 1 day. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.075 lb ai/a per season.
  • bifenthrin (Brigade WSB) at 0.033 to 0.1 lb ai/a. PHI 7 days. REI 12 hr. Do not exceed 0.5 lb ai/a per season. Retreatment interval 7 days.
  • carbaryl (Sevin 4F) at 1 to 2 lb ai/a. PHI 14 days. REI 12 hr. Do not exceed 6 lb ai/a per crop. Cucumber beetles are not specifically cited on the label. Toxic in aquatic habitats. Latex-based formulations, such as Sevin XLR Plus, are less hazardous to bees. Washington and Oregon only.
  • GS-omega/kappa (Spear Biological Insecticide) at 0.2 to 0.8 lb ai/a. PHI 0 days. REI 4 hr. Do not exceed 2 lb ai/a per year.
  • zeta-cypermethrin (Mustang) at 0.028 to 0.05 lb ai/a. PHI 1 day. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.3 lb ai/a per season.