Close-up image of aphids on a Swiss chard plant in a seed crop. Note the blackened stems and leaves as a result of sooty mold fungi growing on the honeydew exudate (sugary, sticky exudate) produced by the aphids, as well as the shriveled white cast ‘skins’ produced by aphids as they moult.

Close-up image of aphids on a Swiss chard plant in a seed crop. Note the blackened stems and leaves as a result of sooty mold fungi growing on the honeydew exudate (sugary, sticky exudate) produced by the aphids, as well as the shriveled white cast ‘skins’ produced by aphids as they moult.

Photo Source: Lindsey du Toit, Washington State University