The species aggregate (probably) willow rosette gall, Rhabdophaga rosaria on Crack Willow behind the dipping pond. Hoping to cut it open to reveal the larva!
Showing posts with label Galls. Show all posts
Showing posts with label Galls. Show all posts
Thursday, 15 February 2018
Leybourne Lakes
The species aggregate (probably) willow rosette gall, Rhabdophaga rosaria on Crack Willow behind the dipping pond. Hoping to cut it open to reveal the larva!
Wednesday, 23 May 2012
Crikey, its hot at last!
A slow walk down the access trail revealed two species of click beetles, the wasp beetle Clytus arietus and several good views of solitary wasps and hoverflies. Here is the first of the click beetles a deep black one. I did wonder whether it might be Hemicrepidius hirtus, a fairly common all black species (including its legs, important in ID) with obvious ridges down the elytra, as seen in these pictures I think.
the pectinate, or if you prefer, serrate, antennae:
and this is the second insect, demonstrating the more usual colour of click beetles, possibly an Athous species such as haemorrhoidalis or an Agriotes species such as lineatus. The larvae of species such as these are common agricultural pests known as wireworms!
These pictures show the angular processes at the posterior margin of the pronotum very clearly!
The next insect is one I have heard of, and seen photos of, before. it is the highly distinctive, and indeed unique, wasp beetle, Clytus arietis, of the family Cerambycidae or long-horn beetles:
There is nothing else like this in the Coleoptera, and whenever I have seen a picture of it, I have wanted to see it in real life. Why it would wish to imitate a wasp, when it is already such a tough cookie, is difficult to imagine. It really does appear to be genuine mimic, because it even makes jerky wasp-like movements on flowers, and a waspish buzz when threatened, presumably to try to convince attackers that it is a genuine wasp! This one seems to have its legs all over the place, and hasn't tucked its pair of flying wings properly under the elytra either.
The elytra are rounded as seen here, and the colour pattern is as seen here. The yellow bands on the square pronotum are typical, with the posterior one divided, as it quite commonly is.The legs are orangeish although the femora are darker. All tibiae have an apical inner spine. Overall the beetle is about 9 - 13 mm long.
The adults are often found visiting flowers and are harmless. The larvae tend to live in dead wood, at first just under the bark, and later in the xylem. The wood used includes dead parts of living trees, dead trees or even fallen dry branches. There is plenty of all of these categories of dead wood along the Access Trail, so the larvae would have had plenty of choice for their homes!
The femora may actually appear quite short and broad, and specifically clavate, particularly in contrast to the apparently much longer thinner tibiae, as demonstrated in this unusual view taken from the rear of the beetle crawling from one leaf to another (unless this is just fore-shortening - it is!):
In the slightly serrate antennae the third segment is clearly longer than the fourth, an identification point worth noting. The first four segments are notably orange in contrast to the darker more apical segments
There were quite a few other insects around, including a few hoverflies. Here is the very common marmalade fly, Episyrphus balteatus, I think a male, very battered, poor thing!
Here is another one, moderately small, but I have no idea of what species it might be. I took a wild guess at Cheilosia but it could well be a whole load of other things as well!
The next hoverfly is another very common one, a male Sphaerophoria scripta, a tiny and very characteristic species.
This is a much bigger hoverfly, but also a very common one, Eristalis tenax, the Drone Fly, with its wide dark facial stripe, and very black rear legs. This particular individual is very dark on the top of the abdomen, usually there are some clear orange sectors here:
Rather nice to see was an immature Common Blue Damselfly, Enallagma cyathigerum, settling quietly from its exploration of the bottom of the hedgerow, with the beautiful lilac colours of a newly emerged adult. The broad blue sub-humeral stripes, the lack of a "Coenagrion spur" on the sides of the thorax, and the dark mushroom on section 2 of the abdomen are indicative of the male of this species, separating it from other blue species such as the Azure Damselfly.
By now I was thinking I was doing really quite well for insects, and a solitary female bee a little further along proved me right when it looked a lot like Andrena chrysosceles. I thought I saw this species at least once before, on the Shepherds Needle down towards the Gravel Pits, but no-one replied to my posting of that insect on ispot for checking. Lets see if the ispot people can help me out this time! This bee was sitting on an ash leaflet on the edge of the Green Lane shaw, grooming itself gently. Because it was fairly still, it allowed a series of photographs, all in the same posture.
The reason I think it is chrysosceles is as follows. It is a smallish Andrena bee, with the typical shape and hairiness for the genus. It is also female because of the long brush of hairs (scopa) on the rear legs. The thorax is lightly coloured with tawny but not fulvous hairs. The abdomen is a relatively shiny glossy black and has very clear close knit bands of silvery hairs running across it (I have seen one picture on the BWARS website that might indicate these bands can be worn away a bit on the top surface, but this may also depend on the light). There appears to be a reddish tuft of hairs at the end of the abdomen. The legs are dark at the base, the femora, but bright gold-orange further down, at the tibiae, and this extends right to the end of the foot, the tarsi and metatarsi.
The male of the species is similar but has white hairs in a moustache on the face, with a white clypeus with two small black dots either side.
There was another female Andrena bee almost immediately, but very clearly of a different species. Actually I now think this is Andrena nitida (2021). This one was much more robust, again with a glossy black abdomen, but larger and more rounded, without the obvious white bands across the abdomen, or the thin white side tufts on the first segments of the abdomen.
the pectinate, or if you prefer, serrate, antennae:
and this is the second insect, demonstrating the more usual colour of click beetles, possibly an Athous species such as haemorrhoidalis or an Agriotes species such as lineatus. The larvae of species such as these are common agricultural pests known as wireworms!
These pictures show the angular processes at the posterior margin of the pronotum very clearly!
The next insect is one I have heard of, and seen photos of, before. it is the highly distinctive, and indeed unique, wasp beetle, Clytus arietis, of the family Cerambycidae or long-horn beetles:
There is nothing else like this in the Coleoptera, and whenever I have seen a picture of it, I have wanted to see it in real life. Why it would wish to imitate a wasp, when it is already such a tough cookie, is difficult to imagine. It really does appear to be genuine mimic, because it even makes jerky wasp-like movements on flowers, and a waspish buzz when threatened, presumably to try to convince attackers that it is a genuine wasp! This one seems to have its legs all over the place, and hasn't tucked its pair of flying wings properly under the elytra either.
The elytra are rounded as seen here, and the colour pattern is as seen here. The yellow bands on the square pronotum are typical, with the posterior one divided, as it quite commonly is.The legs are orangeish although the femora are darker. All tibiae have an apical inner spine. Overall the beetle is about 9 - 13 mm long.
The adults are often found visiting flowers and are harmless. The larvae tend to live in dead wood, at first just under the bark, and later in the xylem. The wood used includes dead parts of living trees, dead trees or even fallen dry branches. There is plenty of all of these categories of dead wood along the Access Trail, so the larvae would have had plenty of choice for their homes!
The femora may actually appear quite short and broad, and specifically clavate, particularly in contrast to the apparently much longer thinner tibiae, as demonstrated in this unusual view taken from the rear of the beetle crawling from one leaf to another (unless this is just fore-shortening - it is!):
In the slightly serrate antennae the third segment is clearly longer than the fourth, an identification point worth noting. The first four segments are notably orange in contrast to the darker more apical segments
There were quite a few other insects around, including a few hoverflies. Here is the very common marmalade fly, Episyrphus balteatus, I think a male, very battered, poor thing!
Here is another one, moderately small, but I have no idea of what species it might be. I took a wild guess at Cheilosia but it could well be a whole load of other things as well!
The next hoverfly is another very common one, a male Sphaerophoria scripta, a tiny and very characteristic species.
This is a much bigger hoverfly, but also a very common one, Eristalis tenax, the Drone Fly, with its wide dark facial stripe, and very black rear legs. This particular individual is very dark on the top of the abdomen, usually there are some clear orange sectors here:
Rather nice to see was an immature Common Blue Damselfly, Enallagma cyathigerum, settling quietly from its exploration of the bottom of the hedgerow, with the beautiful lilac colours of a newly emerged adult. The broad blue sub-humeral stripes, the lack of a "Coenagrion spur" on the sides of the thorax, and the dark mushroom on section 2 of the abdomen are indicative of the male of this species, separating it from other blue species such as the Azure Damselfly.
By now I was thinking I was doing really quite well for insects, and a solitary female bee a little further along proved me right when it looked a lot like Andrena chrysosceles. I thought I saw this species at least once before, on the Shepherds Needle down towards the Gravel Pits, but no-one replied to my posting of that insect on ispot for checking. Lets see if the ispot people can help me out this time! This bee was sitting on an ash leaflet on the edge of the Green Lane shaw, grooming itself gently. Because it was fairly still, it allowed a series of photographs, all in the same posture.
The reason I think it is chrysosceles is as follows. It is a smallish Andrena bee, with the typical shape and hairiness for the genus. It is also female because of the long brush of hairs (scopa) on the rear legs. The thorax is lightly coloured with tawny but not fulvous hairs. The abdomen is a relatively shiny glossy black and has very clear close knit bands of silvery hairs running across it (I have seen one picture on the BWARS website that might indicate these bands can be worn away a bit on the top surface, but this may also depend on the light). There appears to be a reddish tuft of hairs at the end of the abdomen. The legs are dark at the base, the femora, but bright gold-orange further down, at the tibiae, and this extends right to the end of the foot, the tarsi and metatarsi.
The male of the species is similar but has white hairs in a moustache on the face, with a white clypeus with two small black dots either side.
There was another female Andrena bee almost immediately, but very clearly of a different species. Actually I now think this is Andrena nitida (2021). This one was much more robust, again with a glossy black abdomen, but larger and more rounded, without the obvious white bands across the abdomen, or the thin white side tufts on the first segments of the abdomen.
Note the blackish hairs at the rear of the abdomen, though probably not a reliable character.
Friday, 11 May 2012
Finally sunny, but now it's windy!
Along the plum hedge there were small patches of a leaf gall. This might have been Eriophyes similis according to a previous ispot posting, so its up for checking.
The picture below shows a close-up of the the pouch galls on the underside of the leaf, not confined to the margins:
By the poplar windbreak the second(?) one along from the kissing gate had a superb fresh Dryad's Saddle, Polyporus squamosus, growing out of the pollard trunk as well as a decayed growth from last year - and the regrowth of the pollard was very weak, unsurprisingly perhaps considering the extent and duration of the fungal attack. Here are two photos of this year's Dryads's Saddle outgrowth, at different magnifications:
It seems to me that pollarding these poplars has not been an unmitigated success - it seems likely to allow disease in, and create weak points at the pollard regrowth.
On the left of the tarmac path going back towards Victoria Road there were new mushrooms, looking a bit like field mushrooms, but perhaps not quite.
Things have certainly moved on, the elder is coming into flower!
I have been checking the stitchwort (Stellaria media) flowers for pollinators, but found absolutely no takers as yet, At last, today, a visitor, a tiny black bee!
Friday, 4 November 2011
Green Islands at Dene Park
Wow, today has been a bit of a revelation! Firstly a more careful check of some of the leaves on the Beech hedge in the front garden have revealed two old mines of a Stigmella, which must be Stigmella hemargyrella.
I had no idea that either of the Stigmella species was in the locality, nor that this species was present here, in our own front garden. The only time I've identified this leaf-miner before has been at Oldbury Hill on the Lower Greensand Ridge some distance to the North, where I photographed it on the 13th of September. What a turn-up for the books! Perhaps I've missed it at other sites as well, I just can't be sure!
In both pictures below the mine appears to start from near the margin of the leaf, and travels towards the mibrib where it ends, which is the main diagnostic characteristic of Stigmella hemargyrella as opposed to Stigmella tityrella. This is perhaps clearest in the second picture. In both cases you can also see the white spotting of the feeding marks of the Beech Leafhopper on the upper leaf surface.
The major leaf miner found in the hedge, much commoner than the two Stigmella I found today, is the ubiquitous Phyllonorycter maestingella, at least as identified according to the characteristics of the mine. This insect is specific to Beech. Ideally the adults would be raised in order to definitively separate it from Phyllonorycter messianella, which is found on a range of trees, also including Beech. However the ID to species can still be made fairly confidently I think, because of the long tubular mine which is well made within the boundaries of the main ribs of the leaf. P. messianella should be a more oval shaped mine.
Here in the picture below on the underside of a leaf you can see two old Phyllonorycter maestingella mines, both fairly decrepit. The one on the left is as found, but I had opened the one on the right to look for its contents.
Looking closer at the opened mine, I found some aphids sheltering in the old mine. Insects that use the structures of others are referred to as inquilines. I have no information on which species these may be or whether they have been noted by other observers.
Once I'd got over the enjoyable shock of locating Stigmella hemargyrella so close to home, I got Monty into the car and I struggled to get my bandaged foot into my walking boots. We headed off to Dene Park, not really hoping to do anything more than confirm previous sightings of the leaf mines and galls seen there previously, as I thought I was getting to know the Beech trees there quite well by now. The paths were clearly autumnal now, and the overall appearance of the woods has changed significantly since I was last here a week ago.
As quite a few of the Beech leaves have now turned colour, some of the branches are still mainly green, but others are already mainly golden or russet.
Amongst such concentrations of leaves that have already turned, a very few of them have either remained green entirely or remained green in obvious sections, sometimes clearly delineated by their veins. I have heard that this is a sign of hormonal interference from leafminers - and wow - that's exactly what is happening! In the picture below we can see an old Phyllonorycter maestingella mine on the top side of the midrib, which is having some, but little, effect, and two Stigmella tityrella mines on the lower side, which are very clearly causing the lamina all around them to remain bright green, and are likely to be at least recently, if not currently active. The caterpillar on the right (at least) seems to be still within the mine, visible at the end of the tunnel. These Stigmella mines must be Stigmella tityrella because the mines start next to the midrib, and generally travels outward the margin of the leaf, weaving sharply from side to side and each staying with their own segment created by two adjacent major veins.
This was fantastic! The very first time I had identified this insect was in North Wales last weekend, and I've not seen it in Kent at all before, despite the fact that it must have been there, and I'd been looking for it. And yet, I found these two almost as soon as I looked at the Beech trees, by noticing the green island - and there were these two mines!! Its going to be very easy to find some more, if they are actually present here, and they form such clear green islands!
And here is another, again Stigmella tityrella and again very obvious from the green island effect, and again found very quickly. Clearly Stigmella tityrella has been here in Dene Park all along during my autumn visits, just as Stigmella hemargyrella has been present in the garden hedge since at least earlier in the autumn!
Now that I had my eye in, and knew the patterns to look for I found half a dozen other S. tityrella mines, including this one on a leaf that was still completely green. The occupant may have only recently left, leaving the "flap-door" open!
The effect is however not confined just to Stigmella, as seen in this Phyllonorycter maestingella mine found further down the side track. Could this be an example of convergent evolution?
And here we go again, the midge Hartigiola annulipes, a very common gall former on Beech, also seems to have a very effective mechanism of keeping the majority of, if not the whole of the leaf, green. Here is a fairly clear example of the effect, of which I saw many examples.
Here is the gall again, a rather better pair of specimens perhaps, again on a green, quite fresh-looking, leaf
and here that same photo is again, this time in close-up. Note that there was a third gall, but it has been knocked off, just leaving its base.
Some of the leaves have been subject to a fungus leaf spot, which seems to appear on particular clusters of leaves, perhaps due to inoculum potential!
I've seen this damage below illustrated somewhere before, but I cannot remember for the life of me which insect causes this bizarre, if not unique, damage. Its the first time I've ever seen it in real life, but I know I've seen this picture in a book somewhere!
I spent most of our visit today in amongst the various compartments of Beech - they do look great with their russet carpet of leaves and clean woodland floors where the dense foliage of beech has inhibited the development of any significant undergrowth.
I had no idea that either of the Stigmella species was in the locality, nor that this species was present here, in our own front garden. The only time I've identified this leaf-miner before has been at Oldbury Hill on the Lower Greensand Ridge some distance to the North, where I photographed it on the 13th of September. What a turn-up for the books! Perhaps I've missed it at other sites as well, I just can't be sure!
In both pictures below the mine appears to start from near the margin of the leaf, and travels towards the mibrib where it ends, which is the main diagnostic characteristic of Stigmella hemargyrella as opposed to Stigmella tityrella. This is perhaps clearest in the second picture. In both cases you can also see the white spotting of the feeding marks of the Beech Leafhopper on the upper leaf surface.
Here in the picture below on the underside of a leaf you can see two old Phyllonorycter maestingella mines, both fairly decrepit. The one on the left is as found, but I had opened the one on the right to look for its contents.
This was fantastic! The very first time I had identified this insect was in North Wales last weekend, and I've not seen it in Kent at all before, despite the fact that it must have been there, and I'd been looking for it. And yet, I found these two almost as soon as I looked at the Beech trees, by noticing the green island - and there were these two mines!! Its going to be very easy to find some more, if they are actually present here, and they form such clear green islands!
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