Saturday, 14 October 2017
Thursday, 12 October 2017
Trosley Country Park
I found one very likely Phyllonorycter tenerella (Joannis, 1915) Hornbeam Midget mine today - In this case much less than half the width of the available lamina between two side veins, and starting at the midrib running well over half the distance towards the margin. The mine was also inhabited, although having torn it open I may well have sealed the fate of this caterpillar to die before it achieved its further pupal and adult potential!
The picture below is of the mine from the upper-side of the leaf - well eaten and browned, narrow and tightly folded, and long. Interestingly there was some further feeding damage and even webbing at the ends of the mine - perhaps caused by something else, possibly a Tortricoid?
Phyllonorycter tenerella is a species of southeastern England, as well as of Europe. There are reasonable numbers of regular records from Kent, high in 2008 and 2009, as for other leaf-miners I think. David Solly seems to have been very good indeed at finding them over the years!
As far as other leaf miners go, there were also some (not many) Phyllonorycter esperella mines on the upperside of the leaves and quite a few Stigmella probably microtheriella mines running largely up and down the veins. I also saw a few galls caused by what I have called "vein mites" Aceria tenella (Nalepa).
The Hornbeams at Trosley are quite variable, some young, some older, some coppiced, some maidens. This one is a moderately young Hornbeam, apparently a maiden, never been coppiced. It does look possibly a bit root-bound!
This one is another potential maiden, but quite a lot older! This suggests that there hasn't been much coppicing going on in this are of this particular woodland for quite a long time. This might match the history of the wood as a private estate, rather than a worked woodland.
There is an older picture of the grounds on the internet, of unknown date, but indicating their amenity nature at that time.
I saw two trees that were covered in fruit, and wondered why the distribution of fruit was so unequal across the woodland. I collected a couple of dozen fruit to see if they could be germinated.
Wednesday, 11 October 2017
Hazel Wood
Walked down from West Peckham in somewhat murky weather, and into Hazel Wood which had regrown and thickened up considerably since its last coppicing!
The Hornbeam and Oak in the first part of the wood are quite traditional. Further down there is more Sweet Chestnut and Aspen. Birch and Hazel are scattered throughout.
Some of the older Hornbeam and Sweet Chestnuts were in trouble:
On the Hornbeam there wasn't a lot of caterpillar damage, and there were relatively few leafminers and galls. There seemed to be reasonable numbers of probable Stigmella microtheriella and Phyllonorycter esperella, with a very small number of probable Phyllonorycter tenerella.
It was interesting to see that what might have been taken for old summer mines of Phyllonorycter messeniella that were indicated by shortly oblong brown patches had in fact been caused by mines of probable Stigmella microtheriella "cutting off" oblongs of tissue by running up one vein, cutting across from that vein to another, and then down that other, and then cutting back to the first - I need to watch out for this rather unexpected pattern, seen at least three times today!
I was surprised not to see any mite galls in the leaf vein axils, and overall I would say that it was a relatively disappointing walk from both the leafminer and gall point of view. The terrible light and miserable murky conditions did NOT help.
Monty struggled a bit with his back legs.
Tuesday, 10 October 2017
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.
Monday, 9 October 2017
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.
Saturday, 7 October 2017
Oare again
Still lots of twitchers, most of them looking at the Wilson's Phalarope and the Long-billed Dowitcher.
Friday, 6 October 2017
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