Pest Photo

Christine Buhl, Oregon Department of Forestry,

Green alder sawfly

Monsoma pulveratum

Green alder sawfly (Monsoma pulveratum) is an insect pest of Alder trees. It is a native of Europe and North Africa and was first detected in Alaska in 2009.

By quickly defoliating the Alder tree host, this pest poses a serious threat to riparian areas where the alder contributes to nitrogen-fixing of the soil.