An Unusual Snail

Plaited Door Snail, Cochlodina laminata.  High Elms Country Park, 21 July 2012.

I was looking at some unusual plants in the woods at High Elms Country Park when I saw this snail shell apparently attached to one of them.  It seemed unusual, being much longer than it is wide, looking more like a seashell than something belonging to a land snail.  It's not rare, but if you don't look for it you are unlikely to see it.

Here is it in the palm of my hand.  You can see it is quite small.  But when I waited to see if anything was still living in the shell, I found that its owner was smaller still.

The Plaited Door Snail comes out of its shell.    High Elms Country Park, 21 July 2012.

First it pushed out the front and back ends of the part that you eventually see, then the middle squeezed out.  It spread out lengthways and at the same time the eyes appeared on their stalks.  Then it was ready to roll.

What a tiny creature to have such a shell!  Apparently this snail lives on algae, small fungi and decaying wood, usually on the ground in leaf litter.  In humid weather it climbs trees, though that was not where I found it.   If it has to pull that shell up trees it must be quite strong.

The Plaited Door Snail walks away.    High Elms Country Park, 21 July 2012. 

After photographing it I put it back on the plant where I found it.

In these woods you can also find the Roman Snail, which is huge in comparison.

Identifying Agrotis

Three moths of the genus Agrotis.

Suppose you had these three moths in a trap one morning. Or, even more tricky, suppose you just had these photographs. Could you tell what species they are?   There are three moth species you might find that look like this, all in the genus Agrotis.

It's not straightforward. All the main elements you might use to help identify them are the same.   They rest with wings folded far back, the edges nearly parallel. They are a brownish-grey colour with very similar wing markings.  And you know moth markings can sometimes be quite variable, so what can you rely on to tell these apart?

The three candidate species are known as the Turnip Moth, the Heart and Dart, and the Heart and Club.  The fact that all of these have (roughly) heart-shaped and dart-shaped marks doesn't help.

Well, one thing that does help is their size.  That's where you see the importance of photographing them against a measurable background.  These shots aren't meant to be pretty, but useful, and the moths are all sitting on paper marked off in 5mm squares.  (The paper is neutral grey, so that I can eliminate any colour casts while processing the photos.)  So even though they all fill the same space on the screen, you can see that the moth in the middle is noticeable smaller than the others, and the left-hand one might just be the largest by a small amount.

If you look up the forewing lengths of these species you will find that they are variable, but there is a general size differential between the three.  So you would suspect the smallest one of being a Heart and Club, the middle-sized one a Heart and Dart, and the longest one a Turnip Moth.  But that's not enough to be sure.

Now look at their collars.  Two of them have dark lines.  The middle one not so dark as that on the right; it  has a thin dark line with a less dark surround.  That again is typical of the Heart and Club.  So the middle moth is now fairly well identified.

The moth on the right has a thick black collar, which should make it a Heart and Dart.  It looks like a monobrow from the front, but we can't see that view.  But the collar on the left-hand moth seems to be missing some fur at just that point; could it be another Heart and Dart that is just getting a bit old and worn?  Well, males of both the Turnip Moth and Heart and Club have antennae that are pectinate (comb-like) for about two-thirds of their length.  No Heart and Dart moths have pectinate antennae.  You can see the base of the right-hand moth's antennae and they are smooth.  The others both have obvious comb-like structures.  So neither of those could be a Heart and Dart, but the right-hand moth could.  So the right-hand and left-hand moths are now also pretty well identified. 

Another feature that is sometimes useful: The Heart and Dart's darts are usually solid, whereas those of the other two are not.  Also, they are usually thinner and longer than those of the Heart and Club.

Taking all these factors into account, it's always worth checking over them again.  These specimens can now be identified with some certainty from the photos.  From left to right,  male Turnip Moth (right size, no dark collar, pectinate antennae);  male Heart and Club (right size, right sort of collar, pectinate antennae); Heart and Dart (right size, right sort of collar, plain antenna, right sort of darts).   
So, moth identification.  Fun, isn't it?

Variability

Two July Highflyers, Hydriomena furcata.  Jubilee Country Park, 6 July 2012.

One of the tricky parts about identifying moths is that some of them are very variable. We saw these two moths at Jubilee Country Park, and they are both the same species.

The one on the left is what you might normally expect to see. The green and brown patterning can vary quite a bit, but the shape and general impression stay the same. On the right is an all-dark variant, with just a tiny hint of green here and there if you see it close up.

You can still see the shape of the wings, and the darker stripes have the same shape and position.  But it takes an expert to look at these and know at once that they are the same.

And next time, I'll show three moths that look the same, but are not.

Night Visitors

Riband Wave, Idaea aversata forma remutata.   Moth that came to my window on 19 July 2012.

Sitting at my computer, writing up the West Wickham moth trap results for July, I noticed three moths at my window.  I was able to lean out and capture two of them, long enough to get good photos before I released them again.

One was a Brown House Moth which I didn't bother to invite in.  The other two were the Riband Wave above, and a Scoparia ambigualis.

The Riband Wave comes in two forms.  In the other, there is a dark colour between the two lower cross-lines.  The two forms are supposed to be equally common, but I see this one more often.

Scoparia ambigualis.   Moth that came to my window on 19 July 2012.

This is also quite common .  It's one of a group whose larvae eat moss and which look very similar, so I am not completely confident in my identification, though I think it's right.  It was quite active and I didn't let it out of the tube I caught it in.

Later, more moths appeared, and I managed to catch one more.

Hypsopygia glaucinalis.   Moth that came to my window on 19 July 2012.

Another micromoth, this one seen less often, despite the book saying it's common.  So really, considering I didn't have my moth trap out, I did quite well that night!  Especially as one I didn't catch turned up in the house later.

Bee Moth, Aphomia sociella.   Found in my house in Hayes on 21 July 2012.

I thought I had seen a moth come in while I was reaching out and concentrating my attention on catching that last one, but when I had that one safely potted and looked around again, I couldn't find the one I had seen, so thought it must have flown away.  But two days later, this Bee Moth suddenly appeared from behind a plantpot.  I am pretty sure it's the one I missed.  That appearance was lucky for it, because I sent it outdoors again after I had its photo.  It would have starved to death if it had stayed in the house.

OK, this is not a very colourful group, but it was interesting to see them, and I was able to add two new species to my Hayes species list.

A Colourful Visit to Jubilee Country Park

Fat-thighed Beetle, Oedemera nobilis, on a Creeping Thistle, Cirsium arvense.
Jubilee Country Park, 18 July 2012.

Jubilee Country Park is popular just now.  The meadows are flourishing, and that includes the insect life that abounds in them.  The Orpington Field Club visited on 18th July to look primarily for insects.

However, I was with a couple of botanists and we got separated from the entomologists for most of the visit!  Luckily that didn't mean that all the insects stayed with that group.  For example, the green beauty at the top of this post is quite common, but I always like photographing it.

Carcina quercana.  Peleopodid.  Caught by the Tent Peg Lane car park in Jubilee Country Park
on 18th July 2012 and photographed back at home in Hayes.

Yes, I am fascinated by moths at the moment, and it turns out that you can find them anywhere.  I grabbed this one into a little plastic tube before the meeting even started.  Like many small and colourful moths, it looks more or less white in flight.  You have to get it to rest and take a close look to see its real beauty.

At Ray's Pond I saw a damselfly I have not seen before.

Blue-tailed Damselfly, Ischnura elegans, by Ray's Pond.  Jubilee Country Park, 18 July 2012.

Although the early flowers in the pond were over, there were still some of these large buttercups around the edge.

Greater Spearwort, Ranunculus lingua, in Ray's Pond.  Jubilee Country Park, 18 July 2012.

Out in the meadow, some of the grasses were giving a good show.

Smaller Cat's-tail or Small-leaved Timothy-grass, Phleum bertolonii.  Jubilee Country Park, 18 July 2012.

There were many webby nests in the grass full of spiderlings, and wolf spiders were everywhere, carrying their egg-sacs as you have to do if you have no permanent home.

Wolf Spider, Pardosa species, carrying an egg-sac.  Jubilee Country Park, 18 July 2012.

And, of course, there were many butterflies.  This Comma was high in a hedgerow.

Comma, Polygonia c-album.  Jubilee Country Park, 18 July 2012.

It was a colourful visit.  These photos and a couple more are in this web album: Jubilee Country Park, 18 July 2012.

More from Jubilee Country Park

People enjoying the park.  Jubilee Country Park butterfly walk, 15 July 2012.

The park is not just for small groups of butterfly-hunters.  These are some of the many walkers who enjoy it.  Those blue flowers are Chicory, the park's symbol, and the small white ones are Corky-fruited Water-dropwort, which is rare in this part of the country.  Or, it was until the Council's mowers spread it around the local country parks!

On the butterfly walk, the first things we found were moths.  I like moths and spent some time trying to photograph them.  There are several species that commonly fly by day, and others that are easily disturbed.  But this one is not often seen other than at night.

Large Yellow Underwing, Noctua pronuba.  Jubilee Country Park butterfly walk, 15 July 2012.

We didn't know what it was on the day, but strangely I recognised it as soon as I saw the photo.  Here, it is concealing a lower pair of wings which are mostly a vivid orange-yellow colour, and which flash brightly when it takes off.

I chased this next one for a while; it's worth getting a good photo of.

Yellow Shell, Camptogramma bilineata bilineata.  Jubilee Country Park butterfly walk, 15 July 2012.

Only small, but nicely marked.  We also saw some Green Oak Tortrixes and plenty of grass moths, both of which can be expected in a meadow surrounded by oak trees.

And what about this beauty ..

Dung Fly, Scathophaga stercoraria.  Jubilee Country Park butterfly walk, 15 July 2012.

It's a Dung Fly.  But Scathophagas, adult or larva, don't eat dung; they eat other creatures that eat dung.  The larvae are stuck in the dung because that's where the eggs are laid and they can't fly away, but the adults will happily eat other insects wherever they find them.

Then there were these:

Hogweed Bonking Beetles, Rhagonycha fulva.  Jubilee Country Park butterfly walk, 15 July 2012.

Despite some scepticism evinced on the day, these really are known as Hogweed Bonking Beetles, and you can google it to prove it.  It was no coincidence that we first spotted them engaging in copulation on a Hogweed flower.  I have also seen them called the Common Red Soldier Beetle, but that is much less memorable.  Beetles like this are called Soldier Beetles because some of them have  smart red and black patterning which was thought to resemble an old-fashioned soldier's uniform.  Here are some others I posted recently:  Two Cantharids.

It wasn't all insects.  There are lots of interesting plants in the park, including this delicate Smooth Tare:

Smooth Tare, Vicia tetrasperma.  Jubilee Country Park butterfly walk, 15 July 2012.

And other creatures: small mammals, reptiles and amphibia, like this toad I found while looking for moths when I was supposed to be after butterflies.

Common Toad, Bufo bufo.  Jubilee Country Park butterfly walk, 15 July 2012.

Jubilee Country Park Butterflies

The group identifying a butterfly.  Jubilee Country Park butterfly walk, 15 July 2012.

It rained the day before, the night before, the night and day after.  We were very lucky to have a rain-free day for the annual butterfly walk in Jubilee Country Park.  And we were pleased to see that there were lots of butterflies; no rarities, but in places the more common ones were fleeing in flocks as we walked among the grass and wildflowers.

Meadow Brown, Maniola jurtina.  Jubilee Country Park butterfly walk, 15 July 2012.

Here, a Meadow Brown is feeding from Creeping Thistles among grasses and Corky-fruited Water--dropwort.

Ringlet, Aphantopus hyperantus.  Jubilee Country Park butterfly walk, 15 July 2012.

This Ringlet is perched on a Blackthorn leaf among Bramble flowers.

But the closest we got to a butterfly was when one decided to perch on the back of one of the group, giving all but one of us a good look!

Red Admiral, Vanessa atalanta.  Jubilee Country Park butterfly walk, 15 July 2012.

You usually see the upper side of the Red Admiral's wings, because they are so showy.  But I like the undersides.  The colours are muted but the patterning is excellent.  I would have showed the upper side too if the butterfly had given me a good look at it - but it didn't.  When it did open up it was at a sharp angle to me.  But I didn't mind; I like the profiles.

Those three are easy to tell apart, even from their undersides.   The next two, less so.

Small Skipper, Thymelicus sylvestris.  Jubilee Country Park butterfly walk, 15 July 2012.

The Small Skipper and the Essex Skipper can only be told apart (to the naked eye) by the tips of their antennae.  In the Small Skipper, they are partly black; in the Essex Skipper, wholly black, like a cotton bud dipped in ink.  (Although this next one's antennae could have been pale underneath from this viewpoint, in fact they weren't).

Essex Skipper, Thymelicus lineola.  Jubilee Country Park butterfly walk, 15 July 2012.

We saw a few other species as well - Gatekeepers, Commas, Large Whites, at least one Green-veined White - but I didn't get any photographs of them.  Either they were too far away from me, or they moved too fast.  But it wasn't only butterflies we saw that day.  Often, I was chasing other interesting things to photograph instead of concentrating on the butterflies.  Next time I will show some of those photos.