Lullingstone and leafminers with a start to a personal key

Anne and I added ourselves onto The Ash Project's basic tree identification course run by Mike Phillips run at Lullingstone this morning. I came across some Alder mines, at least one of which that fitted Phyllonorycter rajella fairly well from its shape, position and single strong crease, a mine that I don't think I have found elsewhere yet, so very pleasing to see.

Lullingstone is a fairly dry site, and the Alders I was looking at were in the (probably) deliberately planted shaws running uphill from the visitor centre. These seem popular feeding spots with the migrating swallows and martins by the way.

The mines were on the underside of the leaf, close to the midrib and with a single strong crease running longitudinally along the mine. There was one fresh, and several slightly older mines, one of which exactly fitted rajella. The distinguishing feature of the strong crease was new to me, despite the apparent commonness of the species, the Common Alder Midget. The mine is sometimes described as triangular but it may extend further across the leaf making it more rectangular (picture in Eakring Birds). There were several other mines, and although none were entirely diagnostic, any of the three underside species could have been there.

Personal Key to Common Alder Phyllonorycter species 

All these are between the veins on the underside of the leaf,

Near the midribnormally, maybe triangular, single strong crease, Mines in June-July, and again September - October, common: rajella (Lullingstone, Mote Park). Larvae green, if found.

Short, a few weak creases perhaps, June-July, September - October, common: klemannella (Leybourne, Bourne, Mote Park). This is by far the commonest in my limited experience. The larva, if ever found, should be generally quite pale and also rather obviously yellow in the middle sections.

Long, near full half-width of leaf, uncreased, September - October, common: froelichiella. The larva should be grey, if found.


This one, however, is on the upperside of the leaf

Maybe between, maybe over, a vein, with a strong crease, July, and again in October, "common"; stettinensis. UK Moths has: "it forms a small oval mine on the upper leaf surface, with a crease down the centre. Unlike other species that form an upperside mine, the surface is not papery, but quite glossy and heavily creased. The mine begins green and then turns orange or brown when more mature." Wikipedia has that "the frass is deposited in a corner of the mine".  


Grey Alder

Generally similar to Common Alder, except that the long mine of froelichiella is replaced by a different long mine, that of a nationally notable species, strigulatella.


Italian Alder

A restricted list, consisting of just the two fairly shortish species: strongly creased rajella and the only weakly creased klemannella.



One of the Stigmella species was found as well on the Common Alder.

There were also old galls which were probably formed by Acalitus brevitarsus, pouches extending above the leafblade, with now rusty coloured hairs beneath.