Found on willows east of Taumarunui.

By the look of the road north of Taumarunui I would say it is wide spread in the Whanganui river catchment - there were 'wet' looking patches under willows overhanging the road, the same as what appears under oak trees in the UK when there is honydew produced.
I have heard reports that bees are gathering the honeydew this autumn.