What are the red nodules on the twigs of my oak tree? - Ask Extension
Can you identify the red nodules on the twigs of my oak tree? They are attracting ants and wasps, including many Bald-faced Hornets, which are a nuis...
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What are the red nodules on the twigs of my oak tree? #848931
Asked September 07, 2023, 12:04 AM EDT
Can you identify the red nodules on the twigs of my oak tree? They are attracting ants and wasps, including many Bald-faced Hornets, which are a nuisance.
Clackamas County Oregon
Expert Response
These are most likely soft scale insects on your oak twigs.
They look like lecanium scale insects (Parthenolecanium corni or , P. quercifex). Ants, wasps, and yellow jackets are attracted to these. But that can be a good thing, because the scale insect population is often held in check by parasitic wasps.
For more information, see https://pnwhandbooks.org/insect/hort/landscape/common/landscape-scale-insect and https://agsci.oregonstate.edu/nurspest/insects/matter-scale
They look like lecanium scale insects (Parthenolecanium corni or , P. quercifex). Ants, wasps, and yellow jackets are attracted to these. But that can be a good thing, because the scale insect population is often held in check by parasitic wasps.
For more information, see https://pnwhandbooks.org/insect/hort/landscape/common/landscape-scale-insect and https://agsci.oregonstate.edu/nurspest/insects/matter-scale
