Rhopalosiphum rufulum Richards, 1960
on Crataegus, primary host plant
Apterae 2-3 mm, maroon, mottled with green or yellow, with a pattern of mealy wax.
Originally a species from Canada; until present found in Europe only once on the primary host.
on Acorus, secondary host plant
Apterae 1-2 mm, dark brown to blak with dark appendages. On the leaves, sometimes in huge numbers (“the plants looked bespattered with black mud”)
On the secondary host plant in Europe since about 1970.
Blackman & Eastop (2017), Heie (1986a), Şenol, Akyildirim Beğen, Görür & Demi̇rtaş (2014a).