Tuberworm — Phthorimaea operculella


This small moth, or rather its caterpillar, has become an annual pest in the southern Columbia Basin of Oregon and Washington. Some seasons it can invade other areas in small numbers but rarely if ever builds to damaging numbers. In the entire Columbia Basin south of Connell, growers should monitor their production areas for the adults of this insect using pheromone traps as shown below.

Recognizing Adults

 

Markings and color can vary.

Many other small moths like these are found in tuber moth traps placed near native shrubs and herbs.

These are NOT Tuber Moth

Trapping Suggestions:

  • Use Delta style traps
     
  • Replace lures every 6 weeks
     
  • Store lures in freezer until use
     
  • Replace sticky cards weekly to maintain stickiness
     
  • Place traps in or near potato fields, about 12" above ground
     
  • Handle the lures with tweezers.

Foliar Damage


Larvae live in the leaves and stems during the growing season.

Tuber Damage

Tubers exposed at surface are most likely infested. This tuber had 5 large larvae.

Tuberworm Life Stages