Season under way

When I woke up this morning and saw the clear blue sky stretched all the way to the horizon, I knew that today was the day for the season to start. I waited until mid-day before I ventured forth, since insects need time to emerge, inflate and dry their wings and have a few test flights before they start nectaring, not to mention a decent temperature to support flight.


The first specimen I saw was a female Eristalis tenax, which was entirely expected (see my earlier post here). She was on a Dandelion, which flowers for 12 months around here:

Female Eristalis tenax on Dandelion

I chose that shot because it shows the very wide dark facial stripe.

I went to a sunny bank where the Celandines are in full bloom and quickly found a male Platycheirus albimanus, also on Dandelion:  

Male Platycheirus albimanus on Dandelion

I noticed that this close-up shot shows one of the conclusive identification features: a clump of thick, dark bristles under the front leg, near the top:

Male Platycheirus albimanus, showing dark tuft of hairs

Although this isn't the earliest I have seen this species (last year I saw it on March 27th), it is a good indicator that we're catching up at last.

Fungal rusts are usually specific to one family of plants, although some are unique to species. This is Puccinia umbilici on Navelwort - Umbilicus rupestris:

The fungal rust Puccinia umbilici on Navelwort

Notice how fresh the Navelwort leaf is: rusts don't waste any time.

I suppose I should clarify my 'specific to one family of plants' statement. Fungal rusts very often have two hosts which are completely unrelated. This odd situation arises because fungi need somewhere to exist when the primary host loses its annual growth (perennial) or dies altogether (annual). So they tend to live on one host in the summer months before transferring to their overwintering host. The most extreme example I know of locally is Puccinia sessilis which spends the summer on members of the Allium family (in my case on Ramsons), but overwinters on Canary Reed-grass, which I don't have locally. The airborne spores must therefore travel many miles to ensure their overwintering survival. The detail is even more complex, since the fungi have different parts of their reproductive cycles on differing hosts. Sometimes I begin to wonder if these travelling rusts are actually an amalgam of two species. The more I study wildlife, the more complex it becomes.

Finally for today, a shot of the fungus Milesina scolopendrii on Hartstongue fern:

Milesina scolopendrii on Hart's-tongue Fern

This one doesn't need an alternate host, since the fern is evergreen, but as an example of perversity, complexity and downright confusion, other members of the Milesina family (which all infect different ferns) rely on Pine trees as an alternate host.

Signs of high summer

Much of our wildlife is seasonal, with some flower species in bloom early in the year, but others waiting for late summer before they appear. Similarly, some insects are clear indicators that the season is progressing towards its inevitable close at the end of the year. So it is always with mixed emotions that I greet the flowering of Wild Angelica. Angelica is a wonderful source of nectar, so much so that I can find a single flower-head with perhaps 40 insects feeding on it at any one time. Sometimes there appears to be some kind of truce in operation, where predators and prey feed side by side without much aggression being shown, but other species have no such intentions and use the busy flowers as a richly-populated hunting ground. The first heads of Angelica opened this week, so hopefully I'll have some images to show from it in the next few days.

Marsh Cinquefoil is one of the later-flowering species from the patch down beside the bog:

Marsh Cinquefoil

Although it shows some structural similarities, it's quite different from its close relatives Tormentil, Silverweed and even Barren Strawberry, all of which flower in close proximity.

It took me quite a while to realise that all of my local Birdsfoot Trefoil specimens are actually Greater Birds-foot Trefoil:

Greater Birdsfoot Trefoil

I always find Birdsfoot Trefoil near the coast, where it is a much lower plant, almost creeping and prostrate and flowering much earlier, from May onwards. I just assumed that the early flowering was due to coastal warming, but when I began to investigate my local specimens (which flower about now), I found they were all Greater Birdsfoot Trefoil. The plant is much taller and larger in almost all its parts, although the flowers are in clusters containing more flowers than Birdsfoot. The clincher, though, is to sever the stem and examine the cross-section. Greater is hollow, whereas Birdsfoot is solid.

The appearance of Dock flowers is another sign that the season is progressing. These are the (surprisingly beautiful) flowers of  Curled Dock:

Curled Dock flowers

Given the amount of rain we've had, I have seen very few of the larger fungi so far this year, although the usual rusts are all present and doing well. Ergot is also quite prominent on grasses:

Ergot on Sweet Vernal Grass

Ergot is a fungal parasite on grasses, and contains a number of toxins which can cause a wide range of serious effects on humans or other animals that ingest it. These effects range from circulatory problems and neurological imbalances through to hallucination, limb loss, heart damage and spontaneous abortion. Unfortunately for people in the middle ages, cereal crops such as Rye and Barley are grasses affected by Ergot.

St. Marks flies (Bibio sp.) are usually found at the end of April (and I showed a couple at that time), but the red-legged Bibio ponomae emerges in later summer. This is a female:

Bibio pomonae (female)

In common with a number of other butterflies, Green-veined White has two or even three generations per year. This is the first of the second generation that I have seen this year:

2nd generation Green-veined White butterfly

The hoverfly Episyrphus balteatus is readily recognised by the alternating narrow and broad black bands on the abdomen:

Episyrphus balteatus (male)

And this is a little portrait of one of the grey-banded species - Platycheirus albimanus (female):

Platycheirus albimanus (female)

Despite the damp weather, a few interesting moths have come to light. This is the Satin Beauty:

Satin Beauty moth

It's not quite as beautiful as its relatives, but it is an increasing species. It's dependent on conifers, and has spread along with the growth of coniferous plantations.

The Common Wainscot feeds on various grasses as a larva:

Common Wainscot moth

The July Highflyer can be distinguished from other similar species by the diagonal dark slashes at the apex of the wing tip.

July Highflyer

This species has a wide range of larval foodplants, from Willows to Heather, Spruce and Bilberry.

Many of the micromoths can rival or even exceed the beauty of their larger macromoth counterparts. Dipleurina lacustrata is a good example, although it's only 9mm. long:

Dipleurina lacustrata

The first of a couple of new species for me. First, the Fan-foot:

Fan-foot moth

New to my species index.

And a very atypical Square-spot Rustic:

Square-spot Rustic

New to my Species Index.

The Square-spot Rustic feeds on various broad-leaved trees, whilst the Fan-foot is a recycler, feeding on withered and fallen leaves.

Down by the riverside

Much of the river Deele is edged by tall trees which cast a deep shadow along much of its length. This creates a wonderful microclimate, ideal for a combination of woodland flowers and waterside insects. I like to visit at this time of year because it always serves up something of interest.

The area I visited is ripe with the aroma of Wild Garlic (Ramsons) at this time of year: the bank is covered with its delicate white flowers and strappy green leaves:

Ramsons (Wild Garlic) at the river Deele

The flower-heads emerge wrapped in a thin protective sheath which opens to reveal delicate, star-shaped flowers:

Ramsons flower-head with sheath

And a close-up reveals the delicate - almost translucent - nature of the petals:

Wild Garlic flower-head

Two other woodland flowers are also at their best at the moment:

Bluebell:

Bluebell

And Wood Anemone:

Wood Anemone

Having (at last!) got my hands on some spider references, I have been making an effort to fill in some of the gaps in my identifications.

Tetragnatha extensa is usually found near water on low-level vegetation. This one was on Hogweed on the riverbank:

Tetragnatha extensa on Hogweed leaf

Note that its rear right leg is holding the 'tension thread' which allows it to hide, whilst still being able to detect when some insect is struggling in its web. New to my Species List.

Tetragnatha extensa is very closely related to the huge brown spiders that are often found in garages or bathrooms.

Up on the bridge I found Ivy in fruit:

Ivy fruit

And a nice profile shot of the hoverfly Platycheirus albimanus which is everywhere at the moment:

Platycheirus albimanus (female)

I often think that its fascia is very like a human profile.

I'm never quite sure to be dismayed or excited when I see a Pug moth that I don't recognise: I realise that they are very difficult to identify (and that means I'm going to spend quite a while with the books to hand), but there's always the chance I'll find something new. This specimen is the Common Pug, which - strangely - I hadn't seen before:

Common Pug - Eupithecia vulgata vulgata

This moth is normally found from May onwards, so we're still a little early. It feeds on many broad-leaf plants as a larva. New to my Species List.


So that's four new species in a couple of days.

Having mentioned in my last post that St. Marks Flies (Bibio sp.) are out, I got this shot of a male this morning:

St. Mark's Fly - Bibio marci (male)

We can tell it's a male by the large eyes, which meet in the middle. In Bibios, like many other flies, the male has much larger eyes than the female, and often emerges earlier in order to establish his territory. Bibo larvae are root-feeders on many plants, especially grasses. St Mark's day is 25th April, and the flies get their name from the fact that they usually emerge around that date. I've been seeing them for about a week, so the year is still rather early. Bibios are large flies that fly around in large groups - almost swarms - often with their rear legs hanging downwards.

When I was checking the images, I noticed that I had a decent shot of a couple of interesting features:

Bibio marci head (close-up)

Firstly, we can see how hairy the eyes are. Interestingly enough, the hairs don't interfere with the fly's vision: an insect's compound eyes are made up of tubes with sensors at the inner end and a lens at the outer end. These lenses are all arranged on a curved surface, which makes them all point in slightly different directions, which is good for all-round vision. The hairs grow parallel to the tubes, and as a result have minimal impact on the vision, since the line of sight is along the hairs, not across them. These large eyes are used for navigation and for identification of mates, prey and food.

Secondly, we can see the triangle of three ocelli (auxiliary eyes, arrowed) which react very quickly to changes in light intensity, and are used to detect quick motion in order to avoid predators.

A few years ago I took a series of 'bug's-eye' views of plants. Here's a view of a Dandelion seed clock from an unusual perspective:

Dandelion seedhead

 I rather like that shot.

A few of our hoverflies have grey abdominal bands rather than the usual yellow. This is a female Platycheirus albimanus feeding on Dandelion:

Platycheirus albimanus (female)

This is by far the most common species of hoverfly in my garden at the moment.

Still sunny

In this extended period of sunshine, most wildlife has advanced, regardless of the fact that we're still in March. I could see five Small Tortoiseshell butterflies at the same time in my garden yesterday, and that's more than I usually see in a year. Small Tortoiseshells hibernate as adults, so I think the mild winter has allowed a higher proportion of them to survive.

Some plants are flowering at roughly the usual time: I found Germander Speedwell:

Germander Speedwell

Wood Sorrel:

Wood Sorrel

And Common Dog Violet:

Viola riviniana - Common Dog Violet

But this flowering specimen of Herb Bennet is by far the earliest I have ever seen:

Herb Bennet

Field Horsetail is a bit unusual, in that it has early fruiting growths before the sterile green parts are seen:

Field Horsetail - fruiting growth

Again, these are a couple of weeks earlier than I would expect.

If have a microscope, I urge you to put one of those fertile cones on a slide and wait a couple of days for the spores to drop. The spores are fascinating: they have four curled 'legs' which expand and contract with humidity. As they curl and uncurl, they catch onto plant parts and debris, pulling themselves along in order to aid dispersal. This is a plant with 'walking' spores.

Even the uncurling fronds of Hartstongue Fern appear to be earlier than usual:

Hartstongue fern frond uncurling

As soon as the relevant plants are flowering, then their dependant insects appear as well. This is a new moth for me - Mottled Grey:

Mottled Grey moth

The Mottled Grey overwinters as a pupa and feeds on a number of Bedstraws, but the foodplant in my locality will almost certainly be Cleavers.

The Common Quaker feeds on Willow catkins, so March is the normal time to see them:

Common Quaker moth

I spotted a horde of Gerris lacustris Pond Skaters skimming over the surface of the stream beside the path:

Gerris lacustris Pond Skaters

These detect any unfortunate insects that have fallen into the water by sensing the vibrations in the water surface: they move instantly to the precise location in a feeding frenzy that lasts just a short while.

I think I have a new favourite picture. This is portrait of a female Platychierus albimanus hoverfly:

Female Platychierus albimanus hoverfly

I particularly like the way she is highlighted by the petals of the Celandine.

I wasn't too happy with the distance shot of the Small Tortoiseshell butterfly in my previous post, so I'm showing this closeup from yesterday:

Small Tortoiseshell butterfly

Hoverflies increasing in numbers

A couple of the Platycheirus hoverflies have grey markings rather than the more usual yellow. This is a female Platycheirus albimanus, just making her landing approach to a dandelion:

These 'in-flight' shots are attractive, but are also very useful because the wings are open and the abdominal markings are visible and can be used for identification.

Another new (for this year) moth came to light last night: Early Tooth-Striped - Trichopteryx carpinata:

Another Willow feeder.

Bilberry flowers have just opened. They start off a cream colour, but they turn pink within a few hours. These ones are just taking colour: