Pemphigus trehernei Foster, 1975
Populus nigra, Voorne’s Duin © Ben van As
globular galls at the base of of a green shoot, green, reddish around the exit opening. The gall is maximally 2.5 cm large, and invariably solitary.
1-2 mm large aphids on the roots. They are greenish white to yellowish white with greyish white tufts of wax on the abdomen.
Tripolium pannonicum subsp. tripolium (= Aster tripolium).
According to Osiadacz & Halaj also on Solidago virgaurea.
the galls on the primary host are only known through experiments where poplars were “inoculated” with Tripolium aphids.
Blackman & Eastop (2014), Carter & Danielsson (1993a), Heie (1980a), Osiadacz & Halaj (2014a), Roskam (2009a).