The Fly that saw a Ghost

We found this newly-emerged ghost moth (a.k.a. ghost swift moth) Hepialis  humuli yesterday on the banks of the River Derwent, downstream from Blanchland. You can see the remains of the pupal case sticking up through the dead grass just below and to the right of the moth which, judging by the wing damage, had a bit of a struggle to hatch out. Initially I though that little metallic green fly that's standing on the moth might have something to do with the tattered state of the moth and its generally sluggish behaviour (maybe a parasite?) but ........

my suspicions were unfounded - it's Microchrysa polita, which breeds in rotting vegetation and dung and was entirely innocent.  

Starlings

Most years starlings nest in the awning over our backdoor. It's rotten, with a convenient hole in the front and should have been replaced years ago, but whenever I get around to thinking about doing that the next generation of starlings moves in. So they're welcome on two counts - I can legitimately put off the job for another year and I can also enjoy their fine, iridescent breeding plumage (double-click for a better view). When they are prospecting the site it sounds like they're running around inside with hob-nail boots on but once they are incubating eggs it all goes quiet.

When the ultra-demanding fledglings finally emerge they make their parents' life hell for a while, demanding to be fed when they could quite easily feed themselves but.....

... they gradually get the idea.

Fledgling starlings' plumage is deadly dull, compared with the wonderful iridescence of their parents' feathers but that all begins to change in the following year .........

.... when they become sharp-suited, confrontational and raucous.

Midnight Rambler

If you wake up thirsty in the middle of the night and go into the kitchen in bare feet, to get a drink of water, and find something squishy between your toes the chances are it may well be one of these. Yellow slugs Limax flavus are very common in cellars and kitchens.

These large slugs are almost always associated with human habitation but because they are nocturnal many people don't realise they share their homes with them. In this photo you can see the large air pore - the pneumostome - that leads into the animal's mantle cavity, a primitive lung.

The moist, cool conditions of a kitchen at night suit it perfectly, especially if there is a smooth tiled floor to glide over - and it'll probably head straight for any vegetables that might be stored in a convenient place. As dawn breaks it'll glide away again, maybe behind the washing machine or under the sink

This is a slug with a distinct 'hood', from under which two pairs of tentacles protrude.

Although they are quite large the body is very compressible - slugs have a fluid-filled body cavity (a hydrostatic skeleton) where contraction of different muscle layers can make them long and thin or short and fat in any part of their body, so they can squeeze through small gaps - after checking out what's ahead first with those eyes on stalks.

Fully extended, they are up to 10 cm. long.

When yellow slugs come out for a midnight ramble they'll explore every nook and cranny while the rest of the house sleeps, so remember, when you stagger, bleary-eyed into the kitchen for a drink of water at night - they like the feel of smooth, cool ceramic tiles under their feet as much as you do.......

More slugs here

Watching the (Insect) World Pass By...

Sometimes the best way to watch wildlife is to just sit still and let it come to you, and in our garden at the moment the best place to sit is next to this plant - dame's violet a.k.a. sweet rocket a.k.a Hesperis matrionalis. In addition to having a powerful carnation fragrance and being the food plant of the orange tip butterly caterpillar it's a real butterfly magnet and while I watched it was constantly visited by ....

... small whites and ....

... red admirals. Sweet rocket produces such an abundance of nectar-rich flowers that the butterflies are reluctant to leave and just clamber from flower to flower ..

... which gives you plenty of time to admire the intricate patterning on the underside of their wings.

After you've been sitting in one spot for a while you begin to notice things that you might never spot if you were on the move, like this unidentfied green caterpillar resting in the shade of a chive flower stalk.

Then other visitors begin to turn up - this is Tachina fera, whose larva is an internal parasite of noctuid moth caterpillars and which I've never seen in our garden before. It seems to have a real liking for forget-me-nots.

The sweet rocket is the current butterfly attraction in the garden but the focus of bee visits (particularly leaf-cutter bees) is the wood vetch Vicia sylvatica which attracts a constant stream of visitors. This is a very attractive plant that climbs through the surrounding vegetation and produces a large number of racemes of flowers over a long period.

If you sit in the sun for long enough - especially near the garden pond - then this hoverfly Helophilus pendulus almost always turns up. You can find some wonderful photographs of this species laying eggs - and pictures of its eggs and larvae - here

A Tale of Two Tails

A red-tailed bumblebee Bombus lapidarius busy collecting nectar from the chive flowers ....

.... and a little further down the flower border, collecting nectar from a scabious flower - Volucella bombylans, the hoverfly that mimics the bee's colour scheme.

There are two common forms of V. bombylans - this one and another with yellow fur on the body and a whitish tip to the abdomen that mimics the white-tailed bumblebee. The hoverfly larvae feed inside wasps' nests - how they avoid being eaten by wasps is not known. Most years we have a wasp nest in the garden somewhere, so this hoverfly is usually around.

There's more mimicry here

Song Thrushes

The flagstones on our garden path have been littered with smashed snail shells since early spring, thanks to the predatory skills of our resident song thrushes. Last week their fledgelings left the nest and so far they seem to be doing pretty well.........

... although this one still has a lot to learn. This morning it spent ten minutes perched on the back of a garden seat, demanding to be fed by its own reflection in the window.

Beetles

There is a story (almost certainly apocryphal) that when the eminent evolutionary biologist J.B.S.Haldane was once asked by a  clergyman what he had learned about the mind of the Creator from his studies of natural history he replied to the effect that “he must have had an inordinate fondness for beetles”. In the unlikely event that the story is true, he would probably have had the vast diversity of beetles that have evolved in tropical rainforests in mind, but we have a lot of beetle species here in Britain, many of them small and not particularly easy to identify.

These, feeding on buttercup pollen, are (I think) raspberry beetles Byturus tomentosus – a familiar garden pest. Just a few feet away from where this photo was taken there was a large patch of wild raspberry on the edge of woodland and I made a mental note not to eat any of its fruit in the coming autumn, as the beetles’ next move will be to lay eggs in the flowers, where the maggots will feed in the developing raspberries.

This second photograph shows how the way in which a photo is lit affects the appearance of some identification features. The top photo was taken with natural light and the wing cases (elytra) of the beetles look fairly smooth. The lower picture, taken using flash, reveals just how hairy these beetles are [double-click on the image]. I guess that’s why they have the specific name tomentosus – which means covered in hairs (a tomentum). Beetles aren’t usually thought of as being very effective pollinators of flowers but a study by Olle Pellmyr in Sweden in 1985 (The Coleopterists Bulletin 39 (4)  341-345) of a closely related species B. ochraceus suggests that this beetle might well be doing rather a good job. Pellmyr studied the gut contents of raspberry beetles and found that almost all the pollen there (identifiable by its surface pattern) came from just one species – in his study, wood avens Geum urbanum, which B. ochraceus feeds on. These raspberry beetles probably have more catholic tastes (although they do seem to like buttercups and those hairy elytra were probably quite capable of transferring pollen that they didn’t eat between buttercup flowers.

When I was a kid in rural Sussex  we used to call all beetles that looked like this ‘blood suckers’. More accurately, they’re soldier beetles (on account of their smart colours, reminiscent of some regiments’ parade uniforms) and the only ‘blood’ they ever taste is that of other insects, which they often hunt on the flower heads of hogweed and similar umbellifers.

I think this is a Cantharis species but I’m not certain which one. Possibly C. livida. “The Creator’s inordinate fondness for beetles” (or more realistically, natural selection’s  inordinate capacity to exploit genetic variation in subtly different ways) has generated a plethora of tricky-to-identify coleopterans.

Germander Speedwell

When I started out as a student of botany  over 40 years ago there was one vital piece of equipment  that we were expected  to carry at all times – a hand lens. So when we found a plant, like the germander speedwell  Veronica chamaedrys in this  photograph - we could take a really close look at it even if it was an easy one to identify and we knew what it was....

......first scrutinising the floral characteristics, vital for identification, and then the rest of the plant, which often revealed...

........ unsuspected beauty. Germander speedwell has two straight lines of hairs running down opposite sides of the stem. The leaves are in opposite pairs and their orientation shifts through 90 degrees at alternate nodes along the stem - and so do the lines of hairs between successive nodes.

The other key element of the training was to draw identification features like this. These days, thanks to digital photography, it’s easy to record images of them but a simple annotated drawing is a far more effective way of learning the key differences. It involves careful observation, trying to work out the relationships between parts of the object – you really need to look closely at it and understand it. Which is why – I guess –  this simple ID character to germander speedwell has remained firmly stuck in my brain for four decades.

Menace

I found this unusually colourful female cranefly Nephrotoma crocata busy laying eggs in the flower borders in Durham University Botanic Garden. This wasp-like colour scheme looks like a fine example of mimicry,  pretending to be something dangerous as a means of defence, and its jerky movements as it poked its tail end in the soil added to a convincing air of menace. It's harmless though - a 'sheep in wolf's clothing'.

Cycles of Abundance

As spring drifts into summer new insects appear on the scene, briefly flourish and then give way to another species. Recently we've had a virtual plague of St. Mark's flies, whose mating flights are beautifully described by Mark Cocker in today's Guardian Country Diary. This week, in my area at least, it's time for a mass emergence of this...

.....little metallic green weevil that seems to be on every stinging nettle leaf. It's Phyllobius pomaceus (identified with the help of B.N. Davis's excellent Insects of Nettles (Richmond Publishing Co. 1991)). This little weevil breeds on nettles, feeding on the leaves and at the moment every nettle bed has scores of them mating amongst the forest of stinging hairs on the host plant's leaves. They have a short season as adults and will have vanished again by early June, when their larvae feed underground.

This one has strayed onto a hawthorn leaf, overhanging the nettle bed.

Long-tongued Bumblebee

Solomon's seal flowers produce a lot of nectar, so they are a powerful attraction for bumblebees - even if they do have to hang upside down to reach it. Only the bee species with the longest tongues can reach the nectar - this one (Bombus lucorum?) is just about to leave the flower and its long, curved tongue is still extended.

Here you can just see the extended tongue of the bee through the translucent tubular petal

A Cautionary Tale....

A few days ago I posted a picture of what I thought might be a rather rare rough poppy, found beside a pavement in Newcastle. I can now report that it (ahem) wasn’t. It was a bog-standard long-headed poppy. The foliage of the plant that I found was quite different from the surrounding poppies and as the flower had only just opened (and, to be honest, I didn’t look too closely at the time anyway) I couldn’t really be sure whether the seed capsule characteristics were correct. Smitten by doubt, I went back a couple of days later, after the capsule had begin to swell and – sure enough – it was a long-headed poppy Papaver dubium. Mercifully, Blogger had its nervous breakdown immediately after I posted the picture and when it recovered the incriminating post had vanished into cyber-ether.
What have I learned?

1. If you think you’ve found a rarity, it probably isn’t – however much you might like it to be (I knew that anyway, but......... maybe, jusy maybe.....).

2. Double-check, then check again – especially if the ID depends on floral or fruiting characters that are not fully developed.

3. Plants are treacherously variable when it comes to characters like leaf shape, so that two individuals of the same species can look remarkably dissimilar if they are growing under even slightly different conditions.

So, will I be more reticent about tentatively naming things in future? Highly unlikely. I just can’t imagine the day when I lose naive enthusiasm for finding out about anything in nature that seems to be even slightly out of the ordinary, even if I’m completely wrong in interpreting it. Being wrong is an integral element of the learning process. And fortunately organisations like the excellent Botanical Society of the British Isles has an oustanding network of excellent county recorders to exert quality control, filtering out miss-identifications by reckless chancers such as myself when it really matters.

Meanwhile, here are a few more examples of native flora growing in the heart of urban Newcastle, this time correctly identified (I think!).

Ribwort plantain, flourishing in flower beds beside the busy Byker Bank

A female plant of the thalloid liverwort Marchantia polymorpha, with cupules, gemmae and archegoniophores, growing on the wall of a roadside drain, Byker Bank

Broom flowering in a derelict building site beside Portland Road. The flowers have been tripped by bumblebees - these brownfield sites are excellent nesting sites for wild bees.

Bluebells, greater stitchwort and burnet rose on the derelict building site at Portland Road. It was the fabulous scent of the burnet rose that attracted my attention as I walked past.

Wall barley - doing 'exactly what it says in the tin' - at Stepney Bank

White campion flowering under the Byker railway viaduct

Who's Watching Who?

When I stepped outside the front door yesterday morning a stick whizzed past my ear and clattered at my feet. Then I glanced up and one of these - that must have been perched on the gutter above the front door - flew off. Coincidence? I don't think so. I'm guessing it was startled when I hurried out the door, late for work, and dropped the stick. I hope that's the explanation, anyway.

There's something slightly unnerving about a jackdaw's stare. When you're watching them, there's always the feeling that they are watching you. Maybe it's those piercing pale blue eyes with the dark pupil. 

They're wary birds, hard to get close too when they're adults but easy to tame as nestlings. When I was a kid my cousin's friend had one that used to perch on his shoulder and would steal shiny objects that were laying around.

Jackdaws seem perfectly at home on the edge of towns, lurking round rubbish bins, gathering on patches of mown grass, hopping into the road to pick up morsels in between the passing traffic and - if they can find an unguarded chimney pot - blocking your chimney with a nest. Before we humans constructed buildings for them to nest in they nested on cliffs (I was once told that Dawdon, on the coast near Seaham in Durham and graced with some fine cliffs, was originally Daw's Den although I can't find any evidence that this is true. Plausible, though).

Jackdaws have a liking for nesting in church towers and the Rev. F.O.Morris in his History of British Birds (1891 edn) - always a source of entertaining and sometimes unreliable anecdotes - mentions that the bell tower of the Church of Tanesborough in Armagh once became so crammed with sticks of jackdaw nests that the bell could no longer be rung. He lists other instances of spiral staircases in church towers becoming blocked with mountains of jackdaw nests and also mentions that "the immense mass heaped together in the western towers of York Minster, formed a most unfortunate kind of firewood for the last tremendous conflagration that occurred there" - which I think must have been the 1840 fire in that somewhat flammable cathedral.

Hoverfly Yoga

1. Stand with good horizontal posture.

2. Raise back legs above wings

3. Touch tip of wings.

4. Scratch your bum with your feet......







5. .... and finish by scratching your nose with your feet while rotating your head through 180 degrees in both directions.

I wish my joints were still this supple.....

I think this might be a species of Neoascia, possibly N. podagrica. The books say it's associated with 'lush or rich herbage' which pretty accurately describes our garden at the moment - which is where I found it.