New pests threaten Portland’s trees. They could make future heat waves even hotterBy April Ehrlich (OPB)July 12, 2024 10:36 p.m.Two new pests in the Willamette Valley could decimate trees and worsen the ‘urban heat island’ effect that makes some neighborhoods hotter than others📨 Daily news in your inboxSign up today for OPB’s “First Look” – your daily guide to the most important news and culture stories from around the Northwest.EmailPlease leave this field blankSign up