P&PDL Picture of the Week for
September 27, 2004

Sooty Mold on Beech

Gail Ruhl, Senior Plant Disease Diagnostician, Interim P&PDL Director, Purdue University

The sponge-like growth on this branch and leaf collected from a beech tree is an unusual type of sooty mold. Sooty molds are entirely superficial saprophytes that get their nourishment from honeydew-like secretions from insects such as aphids, soft scale, and mealy bugs. The beech tree was infested with a woolly aphid species and thus this specific sooty mold fungus, known as Scorias spongiosa, is feeding on the honey dew excrement from the woolly aphid.

For more information on sooty mold, please see: Sooty Mold-- Is it pollution or is it ALIVE???

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Purdue Plant & Pest Diagnostic Lab Purdue Cooperative Extension Service