Root Borers

Hosts

All fruit trees, but more common in cherry and peach

Biology

Prionus root borer (right) and ten-lined June beetle grubs feed on roots and crowns of cherry and peach.   They can be a problem in sandy soils, and in new orchard sites.

Symptoms/Damage

General tree decline with few other above ground symptoms.  Extensive feeding throughout roots and within crown wood.

Monitoring

Ground bucket traps baited with prionic acid pheromone lures will attract male prionus beetles.

Treatment Threshold

No threshold determined.

Degree Day Model

None

Management Considerations

Soil application of a systemic insecticide may be an effective treatment in young trees with small root systems.  Check the insecticide label to be sure the fruit crop is listed before use. 

Entomopathogenic nematodes and fungi can be effective on June beetle larvae. 

Mass trapping with a pheromone lure can help to reduce prionus populations.