Friday, September 12, 2014
Remnants of an aphid outbreak
Black-margined aphids produce huge amounts of honeydew as they feed. The honeydew quickly covers the leaves with a sugary-sticky film giving the leaves a glossy appearance. Over time, the black sooty mold fungus colonizes the honeydew painting the leaves black (photo at right). The sooty mold fungus grows entirely on the honeydew and does not actually infect the leaves. In fact, you can take your finger nail and scrape the fungus off the surface of the leaves.