Helping Gardeners Put Knowledge to Work

Q:  My serviceberry tree has white fluff under some of its leaves! The affected leaves turn orange and then drop off. Help! What should I do to prevent whatever it is from damaging my tree any more than it already has?

A:  When it comes to garden problems, it’s best to do a little sleuthing before taking any action.

Our “victim” is a serviceberry tree (Amelanchier spp.). In western North Carolina, this early spring bloomer with delicate white blossoms and beautiful early summer berries is a welcome addition to any garden or forest-scape. After its blooms provide bees and other insects with nectar and pollen, its fruits are a favorite of birds and mammals—from chipmunks to bears, as well as people! 

The possible culprits? Like Miss Marple (who is an enthusiastic fan of lovely gardens), we’ll start with what we know. To figure out likely attackers, we turn to Extension horticulture experts! Serviceberry is subject to several insect pests, including pear sawfly, borers, and oystershell scale that don’t match the description. There are pests and diseases from which to choose. Could it be two-spotted spider mites? Or how about lacebugs? Powdery mildew is a common disease of serviceberry—how about that? With so much information available, it can be challenging. 

The local “detective” team. It’s time to visit the Extension Master Gardener HelpLine at the Buncombe County Extension Office, 49 Mt. Carmel Road, Asheville, NC.

The solution. Looking under a microscope at an affected leaf reveals the pest’s true identity: woolly aphids! These handsome little critters look like they are festooned in white feathers. But looks are deceiving. In reality, woolly aphids are covered in waxy strands that make them impervious to insecticidal soap or contact insecticides. Like other aphids, these pear-shaped insects suck sap from plant leaves using their needle-like mouthparts.

 What to do? NCSU Cooperative Extension Hoke County Center notes that “lacewings, lady beetles, and parasitic flies normally keep woolly aphid populations below numbers that rarely damage trees. Try to tolerate damage or presence on trees and shrubs. Populations of woolly aphids rarely get to levels that harm plants despite the appearance of distorted leaves.” So, removing and bagging the affected leaves is all that is needed at this point!

More about serviceberry
Before we close this case, there is one more mystery. Where did the name serviceberry come from? George Ellison writes in the 10 April 2013 edition of Smoky Mountain News:

“Retired Western Carolina University botanist Jim Horton notes in The Summer Times (1979): “Several explanations are advanced for the common name serviceberry … The most interesting, though not necessarily the most accurate, holds that the tree blooms during ‘service’ time; the time when old-timey itinerant preachers were first penetrating the mountains after the spring thaw and performing services…

“In A Natural History of Trees of Eastern and Central North America (1950), naturalist Donald Culross Peattie, who lived for awhile during the 1930s near Tryon, notes: ‘It is from the fruits that the Sarvissberry takes its name, for the word is a transformation of the ‘sorbus’ given by the Romans to a related kind of fruit.’”

Whichever theory you choose to accept, one thing is certain: Amelanchier arborea is a garden favorite!

Article written by Janet Moore, Extension Master Gardener^SM Volunteer.

Learn more
Woolly Aphids Present Sticky Situation
University of Kentucky