Pithanus maerkelii in Washington
MODERATEInsect
Pithanus maerkelii is currently active in Washington. Watch your susceptible trees closely and act early.
About Pithanus maerkelii
Pithanus maerkelii observed in the wild. Research-grade iNaturalist observation.
Symptoms to watch for
Treatment options
Targeted Insecticide Application
Apply appropriate insecticide following label directions. Timing is critical — treat during the vulnerable larval or adult emergence stage for maximum effectiveness.
Biological Control Agents
Introduce or encourage natural predators and parasitoids. Options include releasing predatory beetles, parasitic wasps, or applying Bt (Bacillus thuringiensis) for caterpillar pests.
Infested Material Removal
Prune and destroy infested branches and plant material. Remove fallen debris that may harbor eggs or larvae. Dispose of material away from healthy trees.
Recommended Products & Tools
Helpful supplies for managing Pithanus maerkelii. Always read and follow label directions, and confirm a diagnosis before treating.
Knocks down soft-bodied pests like aphids, mites, and scale crawlers.
Smothers overwintering eggs and crawlers; dormant or summer rates.
Soil-applied protection taken up by the tree for season-long control.
Sharp, clean cuts to remove affected wood — a tree-care essential.
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Need help with Pithanus maerkelii in Washington?
Connect with ISA Certified Arborists serving Washington:
Browse all Washington arborists →Frequently asked questions
Is Pithanus maerkelii in Washington?
Pithanus maerkelii is currently active in Washington. Watch your susceptible trees closely and act early. It was first recorded here on June 28, 2026.
What does Pithanus maerkelii look like?
How do I treat Pithanus maerkelii?
Options include: Targeted Insecticide Application, Biological Control Agents, Infested Material Removal. Confirm the diagnosis before treating, and consider a certified arborist for high-value trees.