Our cottage in Muskoka sits in a beech grove, which, sadly, has been greatly affected by beech bark disease. Many mature trees have died and others are showing signs of infection. However, this sapling is unique. It is covered with a dry, white powdery substance that seems to be alive. Any idea what it is?—John Forsey, Port Carling, Ont.
It’s definitely not beech bark disease. And the reason that the powder looks like it’s alive is because…it’s alive!!!
“The photo appears to show a colony of aphids feeding on a sapling,” says Dan Sharp, an ISA board certified master arborist with Davey Tree Expert Company of Canada. “Young, fast-growing plant tissues are the favourite choice for aphids because they contain more sap and are more supple than mature tissues.”
The powdery-ness is likely the antenna and legs of the insects, says Sharp. “When they’re grouped together, they give the appearance of fuzziness.” He thinks these aphids could be beech blight aphids. “They’re otherwise known as ‘boogie-woogie aphids.’ They earned that name because they seem to ‘dance’ in unison when they’re disturbed.”
Blight? Aphids? Poor little sapling! Or not. “Aphids can look alarming, especially when they gather in large numbers, but they usually cause only minor stress to healthy trees,” says Sharp. “And they’re a key part of the forest food chain. They’ll be eaten by lots of different predators.”
Aww. Dance party’s over.
This article was originally published in the August 2025 issue of Cottage Life.
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