Woolly apple aphid
trees sheltering in cracks and under loose bark. The nymphs become active in late March or April (in the northern hemisphere) and around the end of May, large [...] long, purplish brown and covered by masses of white, mealy wax. The siphunculi are pore-like and the cauda is small. Eriosoma lanigerum overwinters as “naked” [...] Contrary to the situation in America, South Africa, and Australia, woolly aphid does not infest roots in Europe (except rarely if they occur above the ground)