Training Toby at Leybourne

I had a shortish look around some of the mined leaves.

Phyllonorycter rajella on both Alnus glutinosa and Alnus incana (as pictured, on the underside of the leaf)

Phyllonorycter kellemanella = kleeemannella on Alnus glutinosa, one still with an active caterpillar.

Phyllonorycter stettinensis on Alnus glutinosa. The crease runs vertically up this photograph. The mine on the upperside of the leaf spills over a lateral vein.

Note how the brown discolouration has spread, but has not completely replaced the green. 

Fenusa dohrnii on Alnus glutinosa

Incurvaria pectinea on Alnus glutinosa

Maine Coastal Botanic Garden

Carder Bee on Salvia.

American Goldfinch

Drone Fly, on interpretation board.

Cricket (?) on path

Myrtle Warbler, in woods

Downy Woodpecker, on Birch

Downy Woodpecker on Birch

Great Northern Diver, in winter plumage, on Back River, Boothbay.

Dark-eyed Junco:

Witch Hazel:

Sassafras:

Phyllonorycter and Caloptilia on Field Maple

At the far end of the Access Trail woodland shaw, where we put the extra brick footings down the other year, there was a small Field Maple with a few folded leaf tip lobes that looked like Caloptilia mine follow-on folds.

This turned out to be Phyllonorycter acerifoliella, (Zeller, 1839), the Maple Midget, a bi-voltine leaf miner. The mines can be found in small numbers in May and, more frequently, in September and October. These mines are presumably partly the current generation of mines, and so some should really contain larvae or pupae that are about to over-winter.

The pupa should be blackish brown in a tight, thin-walled cocoon that is attached to the floor of the mine; all frass is accumulated in the opposite corner of the mine.

First seen from the upperside, then the underside:

and here is another example:

This is another, more recent mine, which I cannot identify, as it doesn't look at all like typical Phyllonorycter acerifoliella. It could possibly be Phyllonorycter joanissii from Norway Maple, which this mine closely resembles, but this is generally judged very unlikely. In the past Andy Banthorpe has identified this type of mine away from the edge as atypical Phyllonorycter acerifoliella.

Again, first from the upperside, then the underside:

a closer view:

Hopefully these Phyllonorycter acerifoliella folded leaf lobe mines will not be confused again with Caloptilia leaf lobe folds, as I first did!!

Now this looks more like a Caloptilia:

Viewed first from the upperside, then the underside:

On Field Maple, Acer campestre, in the UK this would seem to be most likely to be Caloptilia semifascia  (Haworth, 1828), the "Maple Slender". This is found on the Field Maple in the UK

The very early mine is a gallery leading soon to a small triangular or squarish blotch. Later the larvae move out to form up to three successive tubes or cones by folding the tips of leaves downwards, in which they live. On this plant there were usually only one or two folded leaf lobes per leaf. The larvae are said to be greenish with a lighter head.

The mines are supposed to occur in June - July and the ones shown here do generally look quite fairly old. Pupation is said to be in a flat, parchment-like, shining, yellowish white cocoon on either side of the leaf, but generally near the margin. I imagine that pupae are quite difficult to find in July(ish), and I haven't found any yet. The moth then flies until October, and after hibernating, again in May, before egg-laying.

However, another minor possibility on Field Maple is Caloptilia rufipennella (Hubner, 1796), which is found almost entirely on Sycamore and only rarely on Field Maple in the UK, although apparently on a wider range of Acers, including again Field Maple, on the continent. This species was only first identified on any Acer species in the UK in 1970, and is still a bit local in its distribution although spreading well. Because of its rarity on other hosts, at least according to current records, we can fairly discount it as a likely record in this case. It also has to be said that the information about host preference on different web-sites is quite contradictory in my view.

The initial feeding blotch mines are very difficult to find, and distinguish from other feeding marks, again in my limited experience, and I haven't identified one at all yet. 

A few mines on hawthorn and sallow

Phyllonorycter corylifoliella (Hubner, 1796) on Hawthorn, on a lush plant, heading down towards the Whetsted gravel pits, a fairly classic view of what is said to be a quite common leafminer, from what I can see on the internet. The second image is just a closer crop of the first.

and a closer view:

Here is another mine, again the second image is just a closer view of the first. An older version of the same leaf miner species, or more likely to be Ectodoemia atricollis, with maybe a narrow channel of a mine along the margin of the leaf to start with.

This next one might be a developing Ectoedemia mine, a full depth yellowish mine, with the larva still in it I think! There might be a bit of a thin mine along the edge. Again the second image is just a tighter crop. Ectoedemia atricollis, (Stainton, 1857), the pinch-barred pigmy, which does mine leaves from the end of August through to October.

and this one might be a better developed mine of the same species,

Here is a photo of a galled willow leaf.

Beech in Dene Park

The first Beech, Fagus sylvatica, trees I looked at had some old Phyllonorycter messaniella empty and browned mines, but further round on the north side, there were a couple of perhaps more recent and I think probable Phyllonorycter maestingella mines. And as usual there were some I couldn't make my mind up about.

I think this is pulled quite tight and is probably maestingella, lower side then upper side:

This (I think) is a second example:

Here are some old mines of what is probably Phyllonorycter messaniella.

Here is a new mine, with the caterpillar visible within it, next to a very old mine. There is no sign of any crease in the new mine.

However here is an old mine that still apparently shows sign of a central crease:

There were also some quite chunky brownish Stigmella mines, quite possibly Stigmella hemargyrella, as the egg seems to be away from the midrib. Notice the narrow start and first section of the mine, to the left, which apparently increases in size very abruptly.

Here is another example:

And a third, again starting at the leaf margin and finishing near the midrib, this time with a clear exit hole:

Nothing else, except the common leafhopper marks and the Hartigiola annulipes galls I think.

Late in Dene Park

A few mines about in the gloaming, getting a bit difficult to see!

On the Beech there were a few fairly long thin mines, all apparently deserted (!) of the Beech Midget, Phyllonorycter maestingella (Muller, 1764). I do wonder why this year I find so few occupied mines of this species, and I do seem to find more mines of P. messaniella on Beech, with its wider host range.

Access Trail

Wandered along the shaw on the normal Bourne walk as the light faded this evening, I looked at one of the small Field Maples at the far end and found a few few folded down leaf lobe tips. I wasn't sure whether these folds indicated a Caloptilia as I had first thought, or possibly Phyllonorycter acerifoliella (Zeller, 1839), the Maple Midget. In the end I think at least one leaf tip roll turned out to be the latter, although the revealed mine proved to be empty.

It is regarded as common with the mines occurring in July (presumably this one, hence emptied, with an exit hole) and October.

Eight Mallards overflew in a group. Not much else around, as it was getting very dark.

Fox Covert

Back to Dene Park, and diverting off to Fox Covert and the field beside it.

At the top of the field I found a few small folds at the tip of the lobes of Sycamore leaves, which I thought might be indicative of a Caloptilia species. This could be the Small Red Slender, Caloptilia rufipennella, found in the UK since the 1970s. The moth over-winters, perhaps in an evergreen such as Yew and reappears about spring. The mines are formed in sycamore leaves around, first as a small mine tucked into a vein axil, and you then get usually 3 "leaf tip folds - cones?" of increasing size in which the larvae continue to feed.

Nercwys Forest

A good circular walk here, which I think Toby really enjoyed!

Walkers need to go clockwise to face the cyclists using this anti-clockwise route.

Scolioneura betuleti  (Klug, 1816)

Eastern Bod Petryal

A short morning amble up past the white house in Fron Wyllt. On one of the Wych Elms, Ulmus glabra, there was a long, quite tubular Phyllonorycter mine, very much between two veins. suggesting the Elm Midget, Phyllonorycter tristrigella (Haworth, 1828). This one was showing only limited edge damage to the upper epidermis, as though it perhaps hadn't fully developed. One possible exit hole.

The mining is carried out in July and then in September/October. This one is presumably from the first generation of 2019?

It was unlikely to be Phyllonorycter schreberella, as this is an oval and less contracted mine, possibly across main veins. In addition this is less rarely found on Wych Elm, and also it is commoner in the south of the country (England and Wales), although the distribution certainly does reach North Denbighshire.

Interesting afternoon walk to the east across the Afon Clwyd, along a made track and down a path along the east track, then up through the spruce forest, and back along the Fisheries Road to the main Cerigg-y-drudion road - taking care to take to the verges to avoid the speeding cars.

Bod Petryal in the drizzle

Plenty of Mompha raschkiella mines on the Rosebay Willowherb along the circular path around Bod petryal. Apparently this is the only leafminer found on Rosebay, while there are a range of  other Mompha species on the true Willowherbs, Epilobium. 

The larvae can be found from the end of May to the end of July and from the end of August to the end of September.

The tunnels loop around cutting off tissues (until tissues turn reddish) a large yellowish patch mine is formed.

Fron Wyllt again

Interesting afternoon walk at Fron Wyllt, taking a quick look at the Beech leaves, Fagus sylvatica, on the trees which appear to be planted near the car-park, on both sides of the river. Toby is definitely gradually getting more used to my no-doubt boring stops to look at leaves!

I found about half a dozen relatively short Phyllonorycter mines which seemed to have a strong central crease. Some of these seemed fairly old and abandoned. This would fit in with Phyllonorycter messaniella, which seems to fold and distort the surface of the leaf quite strongly in most of the pictures shown. I saw one particularly long mine, still apparently with a central crease, but there are photos on the internet showing equally long mines that are identified as P. messaniella. These mines could be up against the midrib, or they could be away from it, mostly half way out towards the margin of the leaf. 

However the other possibility is a highly contracted long tubular mine which is said to have several pleats but these might look like just one, and I found three of these, two side by side on one leaf? So Phyllonorycter maestingella was confirmed, and I will come back to this later.


Phyllonorycter messaniella

Phyllonorycter messaniella (Zeller, 1846), Zeller's Midget, is also known as the Garden Midget - arbitrarily? 

According to UK leafmines, the mines are generally active in March - April, again in July and then October, although these dates seem rather tenuous (?). Perhaps its July to October? They don't really fit in with the idea that the third generation only occurs overwintering on the evergreen Holm Oak, December to March. On Beech and Hornbeam this species is said to be found on the lower surface between two adjacent veins, with a sharp fold.

Another more detailed description from the excellent Bladmineerders website is "oval, lower-surface tentiform mine, 9-14 mm long, mostly between two lateral veins. The lower epidermis with a single sharp fold (sometimes forked near its end). Pupa in very flimsy cocoon, that contains a bit of frass laterally and at the rear end".

Polyphagous on woody plants, not uncommon on Beech. However, the Dutch view is that the main host is Oak, although I haven't looked for it there yet. 

It was accidentally introduced into Australia and New Zealand, where it turns out to be regarded as a pest, mainly (and initially drastically) on introduced oaks, etc, but including on members of the native Southern Beech genus, Nothofagus. Initially it ran riot in New Zealand with an average of many mines per leaf until European parasites were introduced, when some degree of control was developed as would be found "naturally" in Europe. 

Phyllonorycter maestingella

The significantly longer mines on these leaves belong to this species, the monophyletic Beech Midget (Muller, 1764). The several folds may appear as one, and the silk is strongly contracted, often leading to a tubular appearance.

It has two broods, the adults flying late April to June, and again in August. The mines are therefore usually active in July and September to October. The insect then hibernates as a pupa, presumably on the ground.

Agelastica alni, by golly

Walking through the pretty woodland nature reserve of Fron Wyllt, I looked at the leaves of some Alders by a small bridge over the rapidly flowing stream.

On the first day I noticed that they had been a bit frazzled.

On the second day I actually thought about it, and wondered whether they were sawfly/slugworm larvae that might be responsible. It sort of occurred to me (very slowly) that I might not have seen this damage on Alder before. It looked a little like the shredding or skeletonisation of beetle larvae damage (as I have seen regularly on Viburmum in recent years) or slugworm damage (as I have seen in the past on Birch). Eventually I found a larva which I thought I recognised as a slugworm style of sawfly larvae. A nasty-looking glossy black caterpillar.

When I got home I saw references to Alder Sawfly, but that is white and spiky, so it was not that. By chance I came across many US references to an Alder Flea Beetle with very similar larvae and blue adults. But this apparently doesn't occur in Europe. I was now intrigued and I finally came across references and photos relating to Agelastica alni, a beetle thought to be possibly extinct, but rediscovered and apparently spreading across several parts of the UK. Oddly enough, it looks very similar to the Flea Beetle from the US.

Here is a photo of a larva on apparently fresh damage, near the base of the leaf.

And another, with slightly older damage,

Here is a photo of older damage, no larva seen.

And a photo of skeletonised leaves against the sky, indicating what potential damage could be done to the Alders along our streams and rivers.

This is the site where the worst damage was seen,