Looks like pine sawfly, Neodiprion sp.

Wyatt Williams
June 28, 2019, 2:42 a.m.

Looks like pine sawfly. Thanks for logging the report and taking good photos. Forest entomologists have been notified and awaiting confirmation. If it is pine sawfly, the damage is quite apparent and looks pretty severe. However, outbreaks of this native insect are short (1-2 years) with little to no tree mortality. I will update this thread when the identity is confirmed

Wyatt Williams
June 28, 2019, 2:45 a.m.

Follow up from Dr. Robbie Flowers, USFS entomologist, Bend OR. Robbie's field report: "Just a follow-up on the pine sawfly defoliation ground checks. It seems to be mostly centered along highway 97 east of Crater Lake and extends from just south of the Crater Lake cut-off (highway 138) to the southern entrance of Silver Lake Highway (highway 676) by Sand Creek Station.

"It seems to be largely restricted to lodgepole pine occurring within a mile or so of the highway corridor. The defoliation was highly variable, with light to severe defoliation often occurring within the same stand as is common to these type of pine sawflies (see attached pics). The new foliage is just beginning to flush, and as many of the red/fed-on needles often break-off, it may look quite different over the next few weeks."

Wyatt Williams
July 10, 2019, 7:15 a.m.

Sawfly outbreaks are often infrequent, short and collapse on their own but can be damaging. Here are some resources to read: https://www.oregon.gov/ODF/Documents/ForestBenefits/Sawflies.pdf
https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5312119.pdf

Wyatt Williams
July 10, 2019, 7:21 a.m.

Hi Loni, you are correct that the pine sawfly outbreak that began in 2019 is continuing this year along the I-97 corridor in central Oregon from Gilchrist/Crescent to south of Chemult. I've been through the area recently and found high populations of pine sawfly. We believe this species is the native lodgepole pine sawfly (Neodiprion burkei) but we are awaiting confirmation from a taxonomist. Several previous outbreaks of this species have been reported from Klamath County. The US Forest Service will be continuing to monitor and map the extent of the infestation. Typically, the outbreaks last for 2-3 years with various levels of damage reported. As this area is currently experiencing drought, it is possible that some tree mortality will occur as the outbreak continues. No treatments are planned as pine sawfly populations return to endemic, non-damaging levels through natural means including predators, parasites and diseases.

robbie.flowers@usda.gov
June 26, 2020, 7:33 a.m.