According to Washington State University, there are 2 types of leafrollers commonly found in Washington apple orchards:
- Pandemis leafroller (PLR)
- Obliquebanded leafroller (OBLR)
If left uncontrolled, both chew through apple leaves and web together leaves and flowering parts of the buds. As larvae grow, they move to feed on the growing shoots, and sometimes continue to feed on the fruit – causing extensive damage and scabbing.
Although they may seem similar at the egg and young larvae stages, it’s important to distinguish the differences between the 2 species so you can tailor your management plan appropriately. As larvae mature, the differences are more easily spotted. Here are some tips to scout for PLR and OBLR:
- PLR larvae have a light green to light tan head and a light green thoracic shield
- Mature OBLR larvae have a brown to black head capsule and a thoracic shield that varies from brown to dull green
- The sides of the OBLR thoracic shield are dark brown to black and the leading edge is white or cream
- AdultPLRs are a tan colored moth, 1/2 to 3/4 inches long with a banding pattern on the wing
- OBLR moths are larger and darker than the PLR
- The leading and trailing edges of the OBLR wing bands are darker than the rest of the wing, not lighter as on the PLR
According to Washington State University, the best strategy to manage leafrollers is to be proactive and control the larvae of the overwintering generation in spring. Experts recommend utilizing insecticide applications in the delayed-dormant period for apples to give the best control of PLR. Additional management tips can be found here for controlling PLR or OBLR as larvae or adults.
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