Asked October 13, 2015, 4:11 PM EDT
Washington County Oregon
Many people in our region have noticed the same numerous small white flying insects during the past several months. They have been identified as ash whiteflies, Siphoninus phillyreae, potentially serious pests of ash trees and certain other woody plants. Very little is known at this time what their activities will be in our region or what sort of management may be needed.
This webpage (late 2015) for commercial growers has some background information and images of infested leaves: http://oregonstate.edu/dept/nurspest/Ash_whitefly.html. (Near the top of the page, notice the link to a local garden show where you can hear an interview with a university-affiliated entomologist.)It’s not yet known if treatment will be needed during the growing season. No action needs to be taken against the adults which are currently active.