Borers

Natural Control of Borer Pests

Insects called borers can be found worldwide across several unrelated groups of insects and reflects their boring larval stage that affects buds, shoots, bark, trunks of trees, shrubs and other plants. Many will develop into beetles (Coleoptera), moths (Lepidoptera), or wasps (Hymenoptera) with some being incredibly target specific. The larval stage (borer) damages plants by destroying internal plant tissue as they feed. More control information on specific species of borers like European corn borers, iris borers and squash vine borers can be found below.

IPM Note: Look for dark or discolored areas with sap and sawdust-like residue on or around host plants. This can help ID affected areas and plan treatments accordingly.

Life Cycle: Timing of life stages throughout the year differs depending on the borer species, your location and environmental conditions, but all borers go through complete metamorphosis with four life stages: egg, larva, pupa and adult.

  • Eggs – Laid when adults are mating on or near the host plant. Common egg-laying sites are on or under bark, in leaf litter/detritus on the ground, and in cracks of tree trunks or branches.
  • Larvae – Once hatched they enter the host plant and begin feeding.
  • Pupae – Some borers pupate in or on the host plant; others drop to the soil to pupate. No damage is done during this stage.
  • Adults – Emerging from pupae, adults mate and seek out optimal sites for eggs to be laid.
Time control efforts according to the target pest's biology for best results. If you have questions, call us at 1-800-827-2847.

Pest Borer Control

  • Trapping and monitoring adults should be started early and continued throughout the season. Sticky traps and pheromone traps can be used in different settings to attract and trap specific insects. Use the trapped adults to correctly identify the pest to be controlled.
  • Introduce Trichogramma Moth Egg Parasites into the growing area early in spring and once adult pests have been spotted. Trichogramma seek out borer moth eggs, laying their own eggs inside them stopping the pest life cycle.
  • Thoroughly spray possible egg-laying sites with horticultural oil sprays when adults are present and once the final frost has passed. Oils smother eggs and reduce borer populations the following season.

Click on the following for more information about specific borer pests or view more control option below.