Looper
Various (Lepidoptera)
0 host plants
Last updated
Western oak looper (also called looper caterpillar) larvae are smooth, slender inchworms that feed on oak foliage. Damage occurs as leaf notching along edges and skeletonization between veins. Multiple larvae can cause significant defoliation of host trees. This species is most problematic in semi-arid regions but can occasionally appear in cooler oak plantings during favorable years.
For landscape oaks experiencing moderate to heavy defoliation, monitor tree recovery the following season. Most oaks tolerate one year of defoliation without long-term damage. Prune heavily defoliated branches to redirect energy. Natural parasitoids suppress looper populations. Avoid broad-spectrum pesticides.
Quick Reference
The Western oak looper feeds mainly on the foliage of the Oregon white (or Garry) oak (Quercus garryana). Mature larvae of the Western oak looper are about 1" long and light brown with black spots when mature. They move in a characteristic "looping" or measuring-worm fashion. The adult moth is yellowish to dark brown. Severe infestations are rare but can result in almost total defoliation of trees. No permanent damage is done by occasional outbreaks.
Cultural Controls
- Many predators and parasites combine to substantially maintain looper populations at low levels.
- The eggs and small larvae are attacked by bigeyed bugs, minute pirate bugs, and other predators.
- Larvae can be hand-picked if found.
- Management-