Saturday, 30 September 2017
Sorbus at Lower Halstow
Unknown Stigmella on the Sorbus outside Judy's house at Lapwing Close, could have been S. magdalenae.
Wednesday, 27 September 2017
The Hucking Estate
Interesting to see the number of Hornbeam within the older woods, and the very few young Hornbeams in the newer plantings.
Phyllonorycter
On the Hornbeams in the older (ASN?) Woods there seems to be a lot of "caterpillar" style damage in the interior of the woods, leaving very tattered leaves indeed. There was also Phyllonorycter esperella on the upperside of the leaves, both remnant signs of the first generation of mines, and newer mines, some starting to bend the leaves up as they tighten (by the way, how physically DO they tighten?). Some of these appeared to have already left their mines. On the underside of the leaves could be seen long narrow mines, strongly narrowed by the contraction of the mines, with clear single creases running along their mid-lines, possibly Phyllonorycter tenerella. There might have been some Phyllonorycter messaniella mines as well.
Stigmella
There were a few Stigmella mines, probably caused by Stigmella microtheriella from their tendency to follow the leaf veins, but Stigmella floslactella may well have been there as well. One mine seemed particularly broader, a feature I believe more associated with Stigmella carpinella. Again, no signs of the hoped for Bucculatrix, Coleophora, Paracrania or Parornix style mines on this site so far.
Aceria
I did find the apparently common gall mites, Aceria tenella, that live in colonies within hairy "spots", each one in one of the leaf axils. Here is a close up showing the reddish-brown discolouration of the hairs induced by the mite in the axil below the midrib - compare this with the relatively tiny clump of whitish hairs in the normal leaf axil above the midrib just to the right. It is also worth noting the very long whitish hairs of the plant lying along the midrib - what on earth can they be for?
Tuesday, 26 September 2017
Getting muddier in Dene Park
Looked at some other leaves for leaf miners today, but also got a snap (with flash) of Phyllonorycter esperella on the upperside of a Hornbeam leaf, just starting to pull the leaf up as it tightens.
Dene Park, 26.09.2017
I also saw a mine possibly created by Parornix carpinella, which would make it a new mine for me!
I had a quick look at a few Beech leaves, and spotted an old friend, Stigmella tityrella, which I have seen both at Dene Park, and also at Bod Petrual near Ruthin. Not a very good photo I am afraid! Notice the browning to the side of the mine itself.
I had a quick look at a few Beech leaves, and spotted an old friend, Stigmella tityrella, which I have seen both at Dene Park, and also at Bod Petrual near Ruthin. Not a very good photo I am afraid! Notice the browning to the side of the mine itself.
Friday, 22 September 2017
Hornbeam leafminers at Dene Park.
Had a lovely walk in Dene Park with Monty, taking a moderately careful look for Hornbeam leafmines. The weather was slightly cool, but nice and sunny - a lovely early autumn day.
None of the fairly accessible and easy to find Stigmella mines from today seemed particularly fresh, so I assume are from the June-July activity. This reduces the accuracy of the ID from species to genus, but almost all the mines seemed fairly thin and had some tendency to follow the leaf veins or midrib for at least part of their activity, so the best of my guesses would be Stigmella microtheriella, one of the two commoner species, and the one noted for following veins. The frass pattern has apparently deteriorated over time, so is now less useful for diagnosis I would say, and there were no larvae present to examine. The remaining frass pattern did appear to be restricted to the centre of the mine as opposed to filling the full width of the mine. However there is another quite likely possibility, Stigmella floslactella, which is equally thin, but rather less tendency for following the leaf veins, and where the frass width initially fills the early stage of the mine. The critical distinguishing feature is the relative thickness of the frass to mine diameter in the early stages. Both species could well be present!
On a few of the smaller leaves there were some notably white mines, which did seem significantly broader and much more convoluted - there is some minor possibility that they were Stigmella carpinella, a rarer mine in the UK, and not specifically noted to be in Kent on the UK Flymines site. There was no frass and there were no larvae to check, so these must remain entirely uncertain, especially as even David Gardiner's 2010 records were not validated.
It will be interesting to wait for the September - October activity, if it isn't there already, to see if diagnosis is any the easier slightly later in the year!
There were also some Phyllonorycter types, some on the underside between the veins, and some (more rounded usually) on the upperside centred above one or more principal veins.
Some of the ones on the underside could perhaps be Phyllonorycter tenerella and if so they should have a fairly strong single crease, and extend from midrib to leaf edge, or nearly so. None I saw completely filled these criteria, but none were fresh, so that might be the explanation. Others could be either Phyllonorycter messaniella (which may also have one strong crease, perhaps forked at the end) or Phyllonorycter ulmifoliella (which may have more and smaller creases), both of which are apparently less extended in length.
This old mine below is on the underside, bounded clearly by the veins, but not long enough to be typical P. tenerella, leaving one of the other two as the most likely candidates for this and the great majority of the underside mines seen on this site. However ulmifoliella is rarely mentioned apart from the UK leafminers site, and although this would indicate that messaniella is the most likely species by a short head, all options must remain open. ACTUALLY this is a mine of Stigmella possibly microtheriella that has "cut out" an oblong of leaf with its travels.
(I went back on Sunday, the 24th, and this time found two possibly fresher mines on the underside of the leaves - oval, but loose, between the veins, about half the distance between midrib and leaf edge, apparently empty, with no visible creases, neither single nor multiple. Therefore I was no further forward - except the continuing gut feeling that the mines are not tenerella, because they are too short).
The leafmine frequently found on the upperside of the leaf is much easier as it is the only upperside Phyllonorycter listed, and so keys out on UK Leafminers as Phyllonorycter esperella (Goeze, 1783), a leafminer specific to Hornbeam in the UK. This species, the adult moth of which is known as the Dark Hornbeam Midget, also occurs throughout mid to southern Europe across to the Near East, and as well as the Hornbeam, it also attacks the Hop Hornbeam, Ostrya carpinifolia where that tree occurs abroad.
This I think is a very common mine in Kent, and I generally find it whenever I look carefully at Hornbeam leaves in woodland, or even quite urban trees (e.g. Hadlow College). I am fairly sure I also saw some in Ryarsh Wood last week. The ones I saw today were generally quite young, relatively small and oval, over the centre of a principal vein. These larvae will have come from eggs laid by the second generation of adult moths, which were on the wing in August.
This one however (the only one found like this) is probably an older mine of this species, demonstrating the upward folding of the leaf as the tentiform mine ages and tightens.
I didn't see any sign of an Eriocraniid type mine today, a long splodgy mine on the edge of a leaf. Eriocrania chrysolepidella is also known as Paracrania chrysolepidella. I was surprised not to find it, given its apparent reasonably widespread (ukflymines) if local (uk leafminers) coverage in the UK, and some existing East Kent records. Nor did I find any Parornix or Bucculatrix mines.
A slow, very relaxed walk, and Monty had a lovely time breaking up sticks in the mud.
None of the fairly accessible and easy to find Stigmella mines from today seemed particularly fresh, so I assume are from the June-July activity. This reduces the accuracy of the ID from species to genus, but almost all the mines seemed fairly thin and had some tendency to follow the leaf veins or midrib for at least part of their activity, so the best of my guesses would be Stigmella microtheriella, one of the two commoner species, and the one noted for following veins. The frass pattern has apparently deteriorated over time, so is now less useful for diagnosis I would say, and there were no larvae present to examine. The remaining frass pattern did appear to be restricted to the centre of the mine as opposed to filling the full width of the mine. However there is another quite likely possibility, Stigmella floslactella, which is equally thin, but rather less tendency for following the leaf veins, and where the frass width initially fills the early stage of the mine. The critical distinguishing feature is the relative thickness of the frass to mine diameter in the early stages. Both species could well be present!
On a few of the smaller leaves there were some notably white mines, which did seem significantly broader and much more convoluted - there is some minor possibility that they were Stigmella carpinella, a rarer mine in the UK, and not specifically noted to be in Kent on the UK Flymines site. There was no frass and there were no larvae to check, so these must remain entirely uncertain, especially as even David Gardiner's 2010 records were not validated.
Dene Park, 22.09.2017
It will be interesting to wait for the September - October activity, if it isn't there already, to see if diagnosis is any the easier slightly later in the year!
There were also some Phyllonorycter types, some on the underside between the veins, and some (more rounded usually) on the upperside centred above one or more principal veins.
Some of the ones on the underside could perhaps be Phyllonorycter tenerella and if so they should have a fairly strong single crease, and extend from midrib to leaf edge, or nearly so. None I saw completely filled these criteria, but none were fresh, so that might be the explanation. Others could be either Phyllonorycter messaniella (which may also have one strong crease, perhaps forked at the end) or Phyllonorycter ulmifoliella (which may have more and smaller creases), both of which are apparently less extended in length.
This old mine below is on the underside, bounded clearly by the veins, but not long enough to be typical P. tenerella, leaving one of the other two as the most likely candidates for this and the great majority of the underside mines seen on this site. However ulmifoliella is rarely mentioned apart from the UK leafminers site, and although this would indicate that messaniella is the most likely species by a short head, all options must remain open. ACTUALLY this is a mine of Stigmella possibly microtheriella that has "cut out" an oblong of leaf with its travels.
(I went back on Sunday, the 24th, and this time found two possibly fresher mines on the underside of the leaves - oval, but loose, between the veins, about half the distance between midrib and leaf edge, apparently empty, with no visible creases, neither single nor multiple. Therefore I was no further forward - except the continuing gut feeling that the mines are not tenerella, because they are too short).
The leafmine frequently found on the upperside of the leaf is much easier as it is the only upperside Phyllonorycter listed, and so keys out on UK Leafminers as Phyllonorycter esperella (Goeze, 1783), a leafminer specific to Hornbeam in the UK. This species, the adult moth of which is known as the Dark Hornbeam Midget, also occurs throughout mid to southern Europe across to the Near East, and as well as the Hornbeam, it also attacks the Hop Hornbeam, Ostrya carpinifolia where that tree occurs abroad.
This I think is a very common mine in Kent, and I generally find it whenever I look carefully at Hornbeam leaves in woodland, or even quite urban trees (e.g. Hadlow College). I am fairly sure I also saw some in Ryarsh Wood last week. The ones I saw today were generally quite young, relatively small and oval, over the centre of a principal vein. These larvae will have come from eggs laid by the second generation of adult moths, which were on the wing in August.
This one however (the only one found like this) is probably an older mine of this species, demonstrating the upward folding of the leaf as the tentiform mine ages and tightens.
I didn't see any sign of an Eriocraniid type mine today, a long splodgy mine on the edge of a leaf. Eriocrania chrysolepidella is also known as Paracrania chrysolepidella. I was surprised not to find it, given its apparent reasonably widespread (ukflymines) if local (uk leafminers) coverage in the UK, and some existing East Kent records. Nor did I find any Parornix or Bucculatrix mines.
A slow, very relaxed walk, and Monty had a lovely time breaking up sticks in the mud.
Thursday, 21 September 2017
Alder leafmines at Leybourne Lakes
I thought I came across a few Caloptilia falconipennela "leaf-edge folds" throughout the Common Alders on the southern side of "The Ocean".
Near the causeway I found a few more mines - including this possible identification of the moth caterpillar Phyllonorycter kleemannella = klemannella (The Dark Alder Midget). The season is only right-ish (mines are supposedly found in May/June and July/August with a possible third generation) but it is supposed to be a common species, and it cannot really be anything else! The caterpillar is supposed to attack the Common, Grey and Italian Alders in the UK, but not the Green Alder. This is a rather poor picture of the mine on the underside of the leaf, not very large, and certainly not extending the majority of the distance between midrib and leaf margin. Just visible near the top are three small creases?
and these pictures are of the larva extricated from the above mine, which is pale and typical of all the Phyllonorycter species except Phyllonorycter froelichiella, where the larva is grey. Once the larva pupates it is found in a white cocoon attached to the roof of the mine, well away from the frass piled in a corner. Before emergence the pupa wriggles to be partly sticking out of the mine, ready to emerge!
and the sawfly Heterarthus vagans on Common Alder, Alnus glutinosa. This common sawfly caterpillar is supposed to attack the Common, Grey and Italian Alders in the UK, but not the Green Alder.
This is probably the pre-pupal stage of Heterarthus vagans, extricated from an apparent pupation disc of the large brown mine of rather indeterminate shape. There appeared to be several discs on the leaf, but actually only one live insect. However the guides suggest that there is normally only one mine per leaf.
Near the causeway I found a few more mines - including this possible identification of the moth caterpillar Phyllonorycter kleemannella = klemannella (The Dark Alder Midget). The season is only right-ish (mines are supposedly found in May/June and July/August with a possible third generation) but it is supposed to be a common species, and it cannot really be anything else! The caterpillar is supposed to attack the Common, Grey and Italian Alders in the UK, but not the Green Alder. This is a rather poor picture of the mine on the underside of the leaf, not very large, and certainly not extending the majority of the distance between midrib and leaf margin. Just visible near the top are three small creases?
and these pictures are of the larva extricated from the above mine, which is pale and typical of all the Phyllonorycter species except Phyllonorycter froelichiella, where the larva is grey. Once the larva pupates it is found in a white cocoon attached to the roof of the mine, well away from the frass piled in a corner. Before emergence the pupa wriggles to be partly sticking out of the mine, ready to emerge!
and the sawfly Heterarthus vagans on Common Alder, Alnus glutinosa. This common sawfly caterpillar is supposed to attack the Common, Grey and Italian Alders in the UK, but not the Green Alder.
This is probably the pre-pupal stage of Heterarthus vagans, extricated from an apparent pupation disc of the large brown mine of rather indeterminate shape. There appeared to be several discs on the leaf, but actually only one live insect. However the guides suggest that there is normally only one mine per leaf.
Wednesday, 20 September 2017
Footling for leafmines at Broadwater Warren
Looked at the Frangula alnus and fairly quickly I located the now long-vacated small spiral mines of what I eventually found out to be Bucculatrix frangutella, the Buckthorn Bent-wing, on quite a few of the leaves. This seems to me to be a delightful oddity. When does the larva decide to straighten its mine out, generally to be followed shortly by its leaving of the mine entirely, and conversion to the habit of window-paning the leaves!
Low down on one particular bush there also appeared to be a lot of window-paning, possibly caused by the further feeding of the larvae.
Sunday, 17 September 2017
Trottiscliffe to Ryarsh Wood and back along the Pilgrim's Way
Chalara has made some progress around the village of Trottiscliffe and a lot in Ryarsh Wood.
Field Pansy and Common Toadflax.
Meopham and District Walking Group
Lovely walk with the group. Broomrape was the plant on the bean field.
Saturday, 16 September 2017
LONG walk Meopham - Luddesdown, etc. with Monty
Bucculatrix ulmella possibly, Phyllonorycter esperella and possibly something like the start of a Parornix on the Hornbeam leaves.
Subscribe to:
Posts (Atom)