• Has not been a general problem since 1994 and introduction of pyrethroid insecticides to control OFM

Site Specific Monitoring

• Cultivar and site specific
• Feeding on nectarines causes direct fruit injury.
• Nectarines should be monitored intensively and have a lower threshold.
  

Monitoring Techniques Thresholds

• Examination of infested terminals and colonies (at least 10 trees per block)
• Peach - 30% infested terminals or 20 active (live) colonies per tree
• Nectarine - 10% of terminals or 5-10 active colonies per tree
• Monitor for the presence of predators in aphid colonies: lady bird beetles and their larvae, syrphid (hover) flies, lacewing larvae.
  

Additional Notes

• Presence or absence of predators may delay need for chemical controls.
• Use of mating disruption technology to control OFM may increase risk of GPA infestation - intensive monitoring necessary, but increased GPA activity may be balanced by increased predator activity.
• Do not spray aphicidies in an attempt to control disease spread (e.g. PPV) - aphicides can actually increase the rate of disease transmission by aphids.

Commonly Used Control Options

• Pirimor now registered but restricted application up to shuck fall
• Thiodan - fair to poor control - not recommended
• Pyrethroids timed for OFM appear to give good suppression of GPA

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