Eriophyes inangulis

A gall mite which causes pouch galls to form on the leaves of Alder, in the angles between the midrib and the primary veins. They appear either alternately or in pairs and may run from the petiole to within two or three veins of the leaf apex. The galls are filled with russet hairs amongst which the mites live, and these hairs often project through to the underside of the leaf to form more or less triangular patches.

Eriophyes laevis also causes galls on alder leaves, but scattered and not confined to leaf vein axils.  However, indeterminate examples can be found, and combinations of the galls are common.  

Gall Adult

State host, and provide a photo

Wherever Alder is found.

Development begins in May and maturity is reached in August or September.

Widespread, but under recorded in Britain.

Status in Leicestershire and Rutland not known.

Eriophyes inangulis is the name given to this gall in the current BPGS key (Redfern & Shirley 2023). The taxonomy of this gall-causer  is confusing; it has previously been called Aceria nalepai.  This is now thought to be an inquiline mite within the gall caused by Eriophyes inangulis; however, this is not certain.  See Bladmineerders (Plant Parasites of Europe) page for Eriophyes inangulis.