Tuesday, 14 April 2015

Traces of decidulation (and aphids)

Autumn is definitely underway and the willows along Whiskers Creek are reacting in the tradional way with yellowing and falling leaves.
What we have noticed this year, for the first time is that where the leaves have fallen on the drive, and then been blown away is that they have left traces behind, which look rather like heron tracks.
 On the concrete of the Creek crossing the traces are more the traditional stains of leaf rot.
My suspicion is that these traces reflect the leaves being covered with honeydew following the invasion of Giant Willow Aphids (Tuberolachnus salignus) for the past 3 months.  The fall of honeydew from the trees was such that the gravel of the drive stuck to our tyres the first time we drove through the shade of the trees each morning.  The aphids have now disappeared for Winter but I expect them back next Spring.

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