Name (also meltau) for the sticky and sugar-rich excrement left behind by various animal pests such as aphids, grapevine smut, scale insects and cicadas on the leaves and berries of vines. Since these insects cannot fully utilise the sugar contained in the absorbed plant sap, they excrete it as a sticky substance. Often this coating is then colonised by sooty fungi, which impedes photosynthesis. The honeydew is highly sought after by certain ant species. If the substance gets into the crop, the taste of the wine can be affected. In the video clip (click to view) an aphid can be seen excreting or spraying away the honeydew. See also other pests under vine enemies.
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Dr. Christa Hanten
Fachjournalistin, Lektorin und Verkosterin, Wien