More Hornbeam at Dene Park

Interesting to walk along the old western boundary of Princes Wood beyond Fox Wood, by the old Hornbeam bank to what is mapped as Claygate Wood, although there were not that many leaf-miners or galls in this area. I had expected more, because of the apparently long history of Hornbeams in this spot.

Again Phyllonorycter esperella, the Dark Hornbeam Midget, was actively present on the upper-surface of leaves, and I tried to find some caterpillars or pupae to rear on to adulthood. However I found neither for certain.

Here are two (one fairly active looking) mines of Phyllonorycter esperella on the upperside of one Hornbeam (Carpinus betulus) leaf. There often seems to be a brownish spot in the centre of an active mine, which could perhaps be frass. However I think the frass is deposited around the perimeter of the mine. The colour tends to be noticeably silver. The mine is said to be flat, and indeed rarely seems to have significant creases. It normally lies over at least one side vein. The outline of the mine is almost rounded, perhaps oval, of very variable size, but apparently not often controlled by the vein pattern.

This is an older mine from the summer, demonstrating the way the leaf has been "pulled up" into a trough by the mine as it tightens. As the mine decays, the leaf surface often seems to recover its integrity and level off. However in this case the "damage" seems more permanent and critical.

Here is another mine, perhaps younger, but broken open and with the leaf beneath looking very good. Perhaps this caterpillar is still at the sap sucking stage, or maybe it is a very shallow feeder. The leaf is also showing the midrib wrinkling associated with Aceria tenella mites.

The leaf on the right is showing an underside leafmine that is short enough to look like an active Phyllonorycter messaniella, perhaps rather unusual to see this so late in the season - unfortunately I didn't collect it. The shoot in the middle has got some good healthy winter buds on it, already developed.

The Hornbeams are starting to turn now, with this interesting pattern of individual leaves being very different in their colour changes, sometimes giving this beautiful pattern.

More leafmines on Hornbeam at Dene Park

Another good walk with Monty, steadily looking for leaf-miners. Today I did reasonably well for Phyllonorycter tenerella, with perhaps half a dozen mines found (none seen before earlier this year - have they just appeared, or have I been missing them??) and even more obvious on the upper-surface were the new blotches of this autumn's generation of Phyllonorycter esperella.

Oare again

Still lots of twitchers, most of them looking at the Wilson's Phalarope and the Long-billed Dowitcher.

Wilson's Phalarope at Oare Marshes

Rather a lovely bird!

Alder leafminers and mite galls at Haysden Country Park

Had a very short (but quite productive) hour at Haysden, where we went along the path towards the Flood Storage Barrier, looking primarily for Alder Leafminers and Galls. There were one or two fair sized Alders by the Shallows (as in the photo below) and then a good line of them along the Straight Mile. There were also a few young plants by the weir at the end of the Straight Mile. All were the Common Alder, Alnus glutinosa.

There were some Agromyza alnivora, and some galls on the leaf surface. The first I saw were small lumps scattered over the upper leaf surface, and slightly "mushroom-shaped" so might have been Eriophyes (Phytoptus) laevis. Even the galls close to the midrib were not confined to the vein axils.

The second type, further along the Straight Mile, were bumps along the midrib specifically in the vein angles, opening below, so were probably Aceria nalepai (Eriophyes inangulis). The usual leafhopper damage is also visible again.

With the Pouch Gall Acalitus brevitarsus, also seen at this site as well as at Leybourne, this brings me up to all the three mite types mentioned in Redfern and Shirley now hopefully identified.

The rusty-brown hairs on the underside of the galls were nice and clear, if a bit dark here.

Also widespread was this rust fungus, mainly on the underside of the leaves, possibly Melampsoridium alni, betulinum or hiratsukanum. M. alni is apparently only found in Asia, while M. betulinum has been noted in the UK (Scotland?) in the past, for example causing a bit of an outbreak in the 1990s. The last of these however is perhaps most likely, a newly introduced rust, since about 2000, potentially causing early defoliation and thus some economic impact on Alder species, particularly Alnus incana.

Going back to the Leafminers, here is what might be the top surface indications of Phyllonorycter kleemannella = klemannella, the Dark Alder Midget, nominally at least small, oval and often away from the midrib. The larvae are supposedly found in May/June and July/August, quite a lot earlier than this particular record, but the Dutch suggest there may be \a third generation increasingly recently.

This "cutout" might have been caused by an earlier leafminer scar that has dropped completely out, and if so, the long and thin shape suggests that it might have been Phyllonorycter froelichiella, the Broad-barred Midget. There are other possibilities though, and even kleemannella = klemannella can be long and thin and look like froelichiella....

As well as probable Aceria nalepai galls, this leaf might just be showing a leaf-mine of Caloptilia falconipenella, as it is right on the margin of the leaf and shows a bit of turning over of the margin. This moth is however nationally scarce B, so the mine might be of something else.

Alder Leafminers at Leybourne.

A successful visit this afternoon, with a reasonable good variety of leaf-mines found, concentrating entirely on Alder. Plenty of birds around, Blue Tits, Coots, Moorhen, Cormorants, Great Crested Grebes.

I concentrated mainly on Common Alder, Alnus glutinosa, but I was also able to spend some time on the Italian Alder, Alnus cordifolia and the Grey Alder, Alnus incana .

One of the really enjoyable finds was one mine of Heterarthus vagans on one of the large Italian Alders at the southern edge of The Ocean. The pupation disc was really nice and obvious, and gives us the possible opportunity of rearing the pupa through to adulthood. I have found this species once before at Leybourne, earlier this month  - although that time I had it down as on Common Alder, when found on the 19th September. It is known to occur on both species.

Another excitement was my first sighting (as far as I know) of Phyllonorycter stettinensis, the only Phyllonorycter to be found on the upperside of Alder leaves. This was seen on Common Alder. The appearance of this Phyllonorycter was noticeably different to the normal matt colours of those on the underside of the leaves - the P. stettinensis mine is a glossy light green, then turning brown. The mine is often over a vein, and may be quite strongly creased.

Another species I could recognise was Phyllonorycter rajella, with its strong crease on the surface of the mine, close to the midrib of the leaf.

More difficult to be sure of were the relatively uncreased oval mines on the underside of the leaves close to or away from the midrib, which I would imagine were mainly Phyllonorycter kleemaniella - but difficult to separate clearly from Phyllonorycter froelichiella, which is also oval and uncreased, but longer, normally over 25 mm long.

Here is a fairly reasonable picture of what I think is a reasonably early (and active) stage of the sawfly mine Fenusa dohrnii in an Italian Alder leaf. It was towards the upper side of the leaf, with frass tending to gather in the centre of the mine (as in one of the Blaadmineerders photos for example), and "spilt out" over a major vein towards the margin of the leaf, as noted for this species. There was only one mine in this particular leaf, but most other factors seemed to fit, and it is a relatively common mine.

The larva takes about three weeks to complete its mine, and then pupates outside, eventually becoming a tiny (c. 4 mm.), mainly black, sawfly. At the moment this mine is relatively translucent and has not yet developed the opaque mid-brown colour, often in the end highly crinkled, of the mine to be seen in its later stages.

Slightly less exciting than some of the other leafminers were reasonable numbers of the usually common Agromyza alnivora, the only fly miner found on Alder species in the UK to my knowledge.

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.