Colorado Potato Beetle

Most insecticides are ineffective against the Colorado potato beetle due to widespread resistance.  It is highly advised to use physical and cultural methods to control the beetle before pesticides are used.  Begin controls as early in the season as possible.  Control techniques are listed in order of effectiveness.

Row covers

• Row covers are specially designed fabrics that let light and water through but keep insects out.  They can be placed directly on top of plants as well as suspended above them.

Physical removal

• Begin looking for the emergence of beetles from the ground in early May and bright orange egg masses in mid May. Squish eggs and beetles with a gloved hand or place beetles in a container of soapy water.
• Starting in late May, regularly check for leaf damage. If located, remove beetle larvae through squishing with a gloved hand or placing larvae in a container of soapy water.
• Continue checking plants regularly throughout the season

Insecticides

• Only begin using insecticides when numbers reach 20 adults/larvae per plant.  All pesticides are most effective on very young larvae and should not be applied on older larvae and adult beetles.  Due to the ability of the Colorado potato beetle to easily form resistance to insecticides, it is highly advised to alternate the pesticide used every season and to closely follow the instructions included with each insecticide
  • Spinosad
  • Bacillus thuringiensis var. san diego
  • Neem