Sun!

This week has been a bit of a surprise: mist in the early morning followed by absolutely clear blue skies all day. Quite delightful, really.

I have been examining my local Hawthorns for miners and came up with this rather interesting specimen:

Stigmella perpygmaeella mine on Hawthorn

It's the mine of the micromoth Stigmella perpygmaeella, which is new to my species list. At point A (the head of the mine) we can see the miner (yellow larva with oval head). But at point B we can see another, different, larva. This second larva has the look of a hymenopteran about it (round shoulders, tapering body) so it will be either a sawfly larva or a wasp larva of some sort. It is clearly heading towards the miner, so it looks like we have a predatory larva in the mine. I knew that miners could be parasitised by Braconid or Chalcid wasps, but this is an entirely new relationship. More research....

While I was working the Hawthorn, I found a few nymphs of the Hawthorn Shieldbug:

Final instar nymph of Hawthorn Shieldbug

This is the fifth and final stage of the nymph: at the next metamorphosis it will be the adult.

Capitalising on the good light, I went up to the local heath to see what I could find. Devils-bit Scabious is one of the latest plants to flower, and the path was lined in purple.

First to catch my eye was this pale pink variant:

Pink Devils-bit Scabious

I have seen this sport before, but it seemed there more around than usual this year. It looks like the pale colour doesn't put off the pollinators.

This shot shows another oddity which I see from time to time:

Viviparous flower of Devils-bit Scabious

The bud at the top is a viviparous flower growing out of the flower below it. It isn't a branch, because the stem arises from inside the lower flower. Not quite sure why this happens.

Here's a shot of the hoverfly Episyrphus balteatus on a normal flower:

Episyrphus balteatus on Devils-bit Scabious

I noticed this cluster of Russulas from the path side and immediately thought "Russula mairei", which is common everywhere around here, but then I realised there were no Beeches around:

Russula emetica - The Sickener

The trees above are Fir and Pine and the mushrooms are growing through Sphagnum. This is classic habitat for Russula emetica, which I have been hunting for perhaps 10 years. This habitat is perfect for it, so I wonder why it has taken so long to get here. New to my species list, at last.

Russula emetica - The Sickener

Russula mairei is known as the Beechwood Sickener, but Russula emetica is known as The Sickener, as you might guess from its specific name.

Flat to the mat

Everything is now progressing at full speed: I saw the first House Martins last week and Swallows will be around in the next day or two.

A few trees are in leaf, with Willow leading the way as usual:

Willow leaves

Hawthorn wasn't far behind, and hedges are now greening up very nicely:

Hawthorn leaves

Notice that the leaves are all in pristine condition. That won't last long once the caterpillars and leaf-miners wake up and start feeding. This synchronisation between insect and foodplant is very well illustrated by the Beech leaf-miner Orchestes fagi: the instant the Beech leaves unfurl, the female weevil lays her eggs on the central vein of the leaf and the miner starts to tunnel towards the leaf margin. A few days later, the mine is complete and the next generation flies off to start the cycle all over again. The synchronisation in this association between two species is critical, since the leaf is only soft enough to eat for the first few days after opening: after that it's too tough. Keep an eye on Beech trees towards the end of the month and you should see the mines within a couple of days of the leaves appearing.

A few flowering plants are now producing flowers more or less all year round and are in flower alongside the spring-flowering species. I suppose we are now warm enough for hardy species to keep going through milder winters. This specimen of Red Dead-nettle has survived the few cold nights and has plenty of flowers already:

Red Dead-nettle

Other flowers that have survived continuously include Herb Robert, Sowthistle, Smooth Hawksbeard, Dandelion, Daisy and Bush Vetch. All of these are currently in flower here.

 
Other species are showing when conditions are right. This specimen of Dark-lipped Banded Snail is one of many colour variants of this common species:

Dark-lipped Banded Snail

I'll show other variants as and when they appear.

I'm always intrigued by the intense colours that can sometimes appear and then seemingly vanish without trace. This Daisy has an intense purple pigment to the tips of the petals, but the fully open flower will be more or less pure white:

Daisy bud, showing the purple petal tips

I suppose there is a fixed amount of pigment that is eventually shared over a larger area. Some fungi show exactly the same effect, getting paler as they mature.

Double delay

After a wonderful April, it has rained every day in May so far, sometimes very heavily. Blogger has also been offline for a few days, so I have a bit of catching up to do.

Worker Bumblebees are very numerous now, although most of the current ones are from the queen's first batch of eggs and are therefore very small. The ones gathering pollen from Raspberry flowers are scarcely larger than a pea:

Worker Bombus lucorum agg.

Hawthorns are in full flower now, and in keeping with the trend this year are bearing many more flowers than usual. Some trees are almost entirely white (and some are almost entirely pink!). The fresh flowers have pink interiors, but that very quickly disappears, leaving a much duller flower:

Hawthorn blossom - "May"

Hawthorn blossom is known as 'May', and is the origin of the northern saying: "Ne'er cast a clout e'er the May is out". Which translates to "Don't divest yourself of warming clothing until the Hawthorn has flowered".

The hoverfly Cheilosia grossa feeds on Thistles as a larva. The larvae can be detected by their effect on the host plant: any thistle that branches from ground level and appears dwarfed can be considered to be potentially 'occupied':

Male Cheilosia grossa

I already showed the first of the Orange Tip butterfly eggs here. The female lays a single egg behind the flower, waiting for the seedpod to develop. She lays only one egg because the larvae are cannibals: any young larva will be consumed by an older one. In the early season, I only ever find a single egg per plant: females detect the presence of an existing egg and will move on to other suitable plants to lay their eggs. At the end of the season, however, all the suitable plants already have eggs and I find what I call the "Let's dump eggs on all the plants in case one might just actually make it" syndrome. This photo shows at least 14 eggs on one plant:

Orange Tip eggs and larva

And top of the class to anyone who spotted the first Orange Tip larva on the seedpod at the front of the picture.

The important thing to realise here is that synchronisation is crucial: if you emerge before the host plant is ready, you will have nowhere to lay your eggs. If you emerge too late, then all the suitable (southwest to south-facing plants on an embankment to catch the sun) plants will already be occupied and your late larvae will have to hope that they don't encounter one of the early occupiers. The window of opportunity is perhaps 14 days. This theme of critical synchronisation occurs time and time again in our wildlife.

The next shot illustrates one of the most stunning aspects of our natural history:

Female Dungfly infected with Entomophthora muscae fungus

The image shows a female Dungfly that has been killed by a fungal infection. The fungus Entomophthora muscae enters the digestive tract and progresses to the abdomen where it multiplies and expands. As it expands, the pink mass begins to break through the abdominal segments as shown above. But now we come to the crucial bit of the exercise: before the fungus kills the fly, it compels the fly to climb towards a high point and then to open her wings. Then it kills her. This combination of high position and open wings affords the maximum opportunity for wind-borne spore distribution for the fungus. So the fungus gains control of the movement of the fly in order to maximise the opportunity for dispersal of its spores.

Slowing down

Things are definitely getting colder now, and the morning dew clearly shows how many spider webs there are on the Gorse:

I wonder what the spider thinks when it sees a host of water droplets in its web for the first time:

This close-up shows that the droplets have even more minute droplets in between them:

We appear to have quite a heavy crop of Haws this year:

Even though most insects have now gone for the year, Ivy continues to provide valuable autumn and winter nectar for the few hoverflies and bees that are still around. A sunny spell will make Ivy worth looking at just in case:
This curious fuzzy bobble on Germander Speedwell took me some considerable time to identify when I first spotted it a few years ago:
It's a gall caused by the plant louse Jaapiella veronicae. If you open the gall you'll find tiny larvae living inside it.

Everything's happening

A few more damselflies today; first a male Azure Damselfly:

And a female Large Red:
Hawthorn blossom, or 'May':

The seeds of Cow Parsley are already forming. These look like beetles complete with antennae. When they eventually turn black, the resemblance is even more convincing.

The next major flower to appear on the hedgerow is Meadow Vetchling, or Meadow Pea. The emerging shoots are very distinctive with their flattened appearance:
A couple of days ago I showed some Lady's Smock - Cardamine pratensis - with four Orange Tip eggs. This is the same plant with a roosting male. The attraction of the plant to the butterfly is extremely strong: most of the roosting specimens I find are on Cardamine.

Lots of colour

I really like this shot of a 7-spot Ladybird roosting in the emptied seedhead of the Dandelion:



I was taught an old saying "nee'r cast a clout until May is out". Roughly translated as "Don't shed any garments until the end of the month of May". But I have been made aware that the original was "Ne'er cast a clout until the May is out", 'the May' being the flowers of the Hawthorn. Looks like I just gained 10 days.


Dung Flies (Scathophagus sp.) are dung eaters when larvae and voracious predators as adults. I'd say that Dung Flies are the most successful hunters I find in the hedgerows. This one is eating pollen.


The first of the yellow Cinquefoils in this area: Creeping Cinquefoil - Potentilla reptans.

But the rain came back. Of course.

Wood Sorrel - Oxalis acetosella - has very attractive flowers that bear close examination. As you can see, the rain returned.


The fertile shoots of Field Horsetail - Equisetum arvense - precede the familiar green growth by several weeks:

Leaves have appeared on the more sheltered Hawthorn bushes: