Star Jelly and Ramshorns

In a friend's garden earlier today, I saw something glistening in a very damp lawn and was pleased to see that it was a slime mould; to be more precise it was Nostoc commune. This is not a rare species (and can be a problem for anyone wanting a bowling-green for a lawn) but, with its green-brown coloration, it is easily overlooked.

Nostoc commune in a lawn at Aston le Walls,
Northamptonshire. 23 October, 2013

In Northamptonshire it was once known as "Star Jelly" from the belief that it grew where a shooting star had hit the earth. A great deal of folk lore is attached to this strange organism. It is technically a cyanobacterium and I have no intention of going into details of its peculiar life; anyone thirsting for details can easily find these from a plethora of web-sites.

The first British reference to it apparently dates the 15th century, when it was recorded from Cornwall. It was referred to as "sterre-slyme" (star-slime) so, even then, a belief prevailed that it was associated with shooting stars. In dry conditions it takes on the appearance if a small piece of dry seaweed, but with the coming of rain it can swell quite rapidly.

Earlier in the day I was pleased to spot a Ramshorn Gall on an oak tree in Byfield Pocket Park. Whereas the Star Jelly has been known since 1440, this gall it has only been known in Britain since 1997. It too is easily overlooked, especially when it has become dry - as was the case with my specimen. Like many galls on oak trees, it was caused by a cynipid wasp, in this case Andricus aries. Since being first found near Maidenhead it has spread at remarkable speed through Britain and by 2010 had been found as far north as Perthshire, Scotland.

Ramshorn Gall caused by the wasp
Andricus aries. Byfield Pocket Park 23 October, 2013

A number of gall wasps are spreading north and west across Europe and many are finding their way into Britain so we may expect more 'invasions' like this in the future.

The Angle Shades Moth

Angle Shades Moth at Harlestone Heath
Garden Centre, nerar Northampton

Strolling through a garden centre earlier today I was pleased to see a fine specimen of the Angle Shades Moth, Phlogophora meticulosa, on some bedding plants. The staff would be advised to get rid of the moth (although I wasn't going to tell them) because, although the adults are not a pest, the caterpillars certainly can be, nibbling away at unopened flower buds and so on. They feed on a wide range of plant leaves including dock, bramble, chickweed, birch and oak but seem to have a particular liking for potted Pelargoniums. These caterpillars are usually bright green with vague yellow markings and a darker green head. 

This handsome moth is quite variable in colour although the basic pattern does not vary. Thus there are specimens with a considerable amount of green in their wing colours whilst others have lovely lilac or pink shades. The example I saw was very obvious against the green foliage but with a background of dead or withered leaves it would be very well camouflaged indeed. 

Research suggests that there may be two species involved, more or less identical to each other in general appearance. One is resident in Britain with the second species being a summer migrant, coming to this country in considerable numbers. (Don't tell the Daily Mail!)

Robin's Pincushion

Most country dwellers will be familiar with this structure, found on various species of wild rose. In many books it is referred to as the rose bedeguar gall. Whatever one chooses to call it, it is a most remarkable structure and has been the subject of much research. 

Robin's Pin Cushion. Byfield Pocket Park
16 October, 2013

The gall is induced by a tiny (3-4 mm long) cynipid wasp, Diplolepis rosae, and it begins to develop when the wasp lays its eggs in the tissues of a rose leaf bud. Up to 100 eggs may be deposited and, as the eggs develop, the rose is somehow stimulated to produce the extra tissues to form the gall. Just how the rose is induced to produce these tissues remains something of a mystery. Inside the gall the wasp larvae begin to develop, taking their nourishment from the surrounding plant cells. Sometime in the autumn, usually around late October, the larvae are full-grown. They have stored up considerable reserves of fat, and these will sustain the banana-shaped grubs through the winter. They spend the winter in a form of hibernation known as a diapause. Round about the beginning of May the grub goes through a final moult and a few days later the wasp - now an adult - chews its way to the outside world. 

A closer view of the same gall.

Extraordinary though all this is, the story of the gall now becomes far more complex. As it develops more insects, mostly other species of wasp, begin to move in. Some will feed on the plant tissues but others, known as parasitoids, will begin to feed on the original wasp grubs. Eventually an exceedingly complex community develops and so far 14 different species have been identified from these galls, with even more from the galls on the continental mainland. The precise way in which all these "inquiline" species interact is still far from clear and to explain even a little of what is going on would make this a mega-blog. I would commend a fascinating article by Simon Randolph in British Wildlife Vol 24, No 1.  Members of the British Plant Gall Society are helping to take research further

The Sore-bottomed Shieldbug

This isn't its recognised name of course; I am referring to the Hawthorn Shieldbug, with its curious Latin name of Acanthosoma haemorrhoidale. The genus name is straightforward, for 'acanthosoma' simply means 'spiny bodied'. It is the species name which is puzzling - until, that is, the rear end of the bug is examined. It is a bright pink, leading Linnaeus - who must have had a sense of humour - to conclude that the unfortunate creature was suffering from piles!

As one would expect, this bug is common on hawthorn bushes although observations made in Surrey ("Shieldbugs of Surrey" by Roger Hawkins) show that it can be particularly abundant on some species of Cotoneaster, especially Cotoneaster x watereri. I saw it in Byfield Pocket Park earlier today on Bramble and it kindly sat still while I photographed it.

Hawthorn Shieldbug, Acanthosoma haemorroidale
Byfield Pocket Park.  3.October, 2013

September is the best month to see this bug. Odd specimens turn up at other times of the year but adults are most numerous in early autumn. They then go into hibernation in late October. This is quite a large bug, but its chestnut-red and green body matches the berries and leaves of hawthorn and it can quite easily be overlooked. As with most of its relatives, any attempt to handle it will leave a pungent smell on the fingers - the same smell that deters would-be predators

Hawthorn Shieldbug, showing its "sore bottom"

It is necessary to turn the bug over to see the red patch at the base to the abdomen. (Bug-lovers will be pleased to know that, having had its nether regions photographed, the plucky creature recovered and I was able to set it free.)

Brighton Break

Elms in a Brighton street. 27 September 2013

In a word association game, anyone given the word 'Brighton' will inevitably respond with 'elms'. No? Well, they should. The first photograph shows a rather mundane street in Brighton but the roadside trees are elm. Anywhere else in Britain this would be a most unusual sight but in Brighton there are thousands of such trees - over 17,000 at the last count. 

A 'Weeping Elm' near to the Royal Pavilion.
26 September, 2013

Elsewhere in the town there are finer examples, some even being rather famous. The next example, a specimen of Ulmus glabra 'Horizontalis' was photographed in a park adjacent to the Brighton Royal Pavilion. It might be assumed that these trees are naturally resistant to Elm Disease but in fact their survival is due to a very well organised 'sanitation' program which quickly identifies, and deals with, any outbreak of the disease. As most people
are aware the disease is caused 
by a fungus carried by the beetles, Scolymus scolymus and Scolymus multistriatus. 

No doubt I am a philistine, but I found this park far more interesting than the Royal Pavilion. Of course there were the usual street pigeons (feral Rock Doves) and Wood Pigeons strutting around but, staying aloof from these, was a Stock Dove. This is a slightly less common species, perhaps often overlooked,  and lacking any of the bold markings borne by its relatives.

Stock Dove in the gardens adjacent to the Royal
Pavilion, Brighton. 26 September, 2013

A calliphorid fly, Stomorhina lunata, taken in gardens
beside the Royal Pavilion, Brighton.
26 September, 2013

I was stooping down to take a closer look at this bird when I spotted a rather unusual fly on nearby foliage. Fortunately (but not for the fly) I managed to catch it and, once home,  was able to identify it as Stomorhina lunata. This relative of the blowflies is described in Peter Chandler's Checklist as an "occasional vagrant". It is more at home in southern Europe where it apparently feeds on locust eggs. There are yellow bars on the abdomen, rather like some hoverfly species, and there is striping on the eyes reminiscent of certain Horse Flies. Is it established in southern England? If it is breeding here it may feed on grasshopper eggs, after all a locust is really a large grasshopper. 

Another insect to catch the eye was the familiar Green Shieldbug, Palomena prasina.
Although it is bright green throughout the summer months, it takes on dull brown colours to overwinter. The specimen I photographed was in a transitional stage; it will eventually hide itself away under dead leaves or some such material and remain concealed until spring.

Green Shieldbug, Palomena prasina, in the gardens
of the Royal Pavilion, Brighton 26 September, 2013

Indian Pokeberry, flowers.
Gardens beside Royal Pavilion, Brighton

By and large the park was planted up with commonplace species but I was pleased to see a few plants of Indian Pokeweed, Phytolacca acinosa in the flower beds. This species is frequently bird-sown and the fact that the plants weren't labelled suggested that they weren't a deliberate planting. 

Indian Pokeberry , Phytolacca acinosa ,in fruit.
Brighton, 26 September, 2013

Although birds eat the berries with impunity they are poisonous to humans unless carefully cooked. It has a long flowering season; some flowers were yet to open but elsewhere there were fully ripened fruits.   

I could have spent more time in these gardens, and many people less strong-willed than myself would have lingered on to give more attention to the fungus, Melampsora hypericorum affecting the leaves of a St John's Wort. 

Hypericum rust, Melampsora hypericorum,
affecting St John's Wort. Brighton, 26 September, 2013

...but there were other places to visit and other scenes to enjoy and I tore myself away. 

Lepidoptera: obvious - and less so

Lepidoptera - butterflies and moths - are familiar to us all from early childhood. We soon recognise butterflies, such as the Comma, as they tend to be colourful and diurnal; moths are often duller and nocturnal. In fact many 

Comma, Polygonia c-album, on Buddleia
Byfield, 24 September, 2013

moths are also diurnal but there is another problem: many moths are small - and some are very small indeed. For this reason many are referred to as micro-moths. They are abundant in most habitats but obviously they are easily overlooked. Fortunately their presence may often be revealed by other clues - leaf mines. These are created by the tiny larvae as they munch their way through a leaf between the upper and lower surfaces. Often the mines are obvious, but in some cases they can easily be missed. A case in point is that created by the Poplar Bent-wing, Phyllocnistis unipunctella. It looks rather like a faint snail trail across the leaf, in this instance a Lombardy Poplar beside the playing fields in Byfield. Luckily the bright sunlight helped me to spot it.                       

Mine formed by the larva of the Poplar Bent-wing,
a tiny moth, Byfield, 23 September, 2013

A rather different form of mine is that of the Hornbeam Midget, Phyllonorycter tenerella. The Hornbeam is not a native tree in Northants but is widely planted, and this tiny moth has increased its range as a result of these plantings.

Mine of the Hornbeam Midget, Phyllonorycter tenerella
Byfield playing fields, 23 September, 2013

I am confident that all my readers - both of them - will now go dashing out to seek these fascinating mines. A word of caution is therefore called for: moths are not the only insects to exploit this leafy niche. Numerous two-winged flies also create very similar mines and the final photograph shows the mine of an agromyzid fly, Ophiomyia beckeri. This is a widespread species but I am not aware of any other records of it from Northamptonshire.

Leaf mine on sow-thistle made by the larva of a fly,
Ophiomyia beckeri. Byfield. 10 September, 2013

In my next blog I'll try to be less self-indulgent and write about something interesting!
  

Mud, mud, glorious mud

Adjacent to my friend Harry Ferminger's house is a pond with a surface area of around 500 square metres (Does that make it a small lake?). I asked Harry who owns it. He said that he wasn't sure but didn't think it was his! 

Anyway, yesterday I decided to have a stroll round it and so, sweep net poised, I gave it a recce. The first thing to catch my attention were the waterside plants. Cattle regularly visit the pond/lake to drink and their trampling has created a very interesting uliginous environment with Celery-leaved Buttercup (Ranunculus scleratus), Red Goosefoot (Chenopodium rubrum) and Marsh Cudweed (Gnaphalium uliginosum) present. None of these is rare but, with the loss of this kind of habitat, all are far less common than was once the case.

Marsh Cudweed beside pond near Byfield.
16 September, 2013 

No one would regard Marsh Cudweed as a spectacular plant and, with its small, brown, petal-free flowers it is hard to accept that it is in the same family - Asteraceae - as Dahlias and Marigolds.

Celery-leaved Buttercup beside pond.
Byfield, 16 September, 2013

The Celery-leaved Buttercup is also a disappointment for those familiar with its larger flowered relatives. It is a plant demanding close inspection to appreciate its features. It also required me to kneel in mud to get a decent photograph and I drew the line at that. 

A closer view of the same plant.

As a child I was familiar with this little buttercup at Kingsthorpe Mill and elsewhere. I rarely see it nowadays so I was delighted to make its acquaintance once again.

Red Goosefoot is another frankly dull plant. It is probably most often to be seen on manure heaps, and many people would probably argue that it is an appropriate habitat for this member of the Amaranth Family, Amaranthaceae. Until recently it was always placed in the Spinach Family, Chenopodiaceae, but times are a-changing. The pondside mud in which it was flourishing was probably enriched with cattle droppings so, although the plant is edible ("a delicious addition to salads", claims one website) I didn't exactly salivate and the plants remain where I found them.