Eriosoma lanuginosum (Hartig, 1839)

Morphological characters

1.2-1.4 mm.
Apterous: light yellow or pink and sometimes red.
Alate: dark green to black with diffuse stripes on abdomen, antennae short, cornicles reduced to a pore, cauda short and half-moon shaped, on wing medial vein once-branched.

Life cycles

Dioecious holocyclic.

Host plants

Primary host: Ulmus (elm).
Secondary host: Pyrus communis (pear).

Particular characteristics

The apterous forms secrete white waxy filaments.

Agronomic impact

E. lanuginosum is rare and not a great threat on pear in France.
The species establishes itself on the underside of leaves. It causes the formation of large irregular bladder-like galls (see photo above) that may reach 6-8 cm diameter