Friday, 27 July 2012

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.

Saturday, 14 July 2012

A little heat

When it rains, flying insects - quite understandably - keep a very low profile, and once the rain stops it takes a couple of days for them to emerge in any great numbers. After a couple of dry days, though, it seems that we have had a fresh start and everything is out again.

True Crane Flies are recognisable by their very long legs:

Crane fly Tipula fascipennis (female)
The larvae of Craneflies are the 'leatherjackets' that eat the roots of grasses, and can remain underground for over a year.

There are many species of Cranefly, and distributions are generally governed by availability of the favoured foodplant. The specimen above has a very distinctive white flash that extends to both edges of the wing, leading us to Tipula fascipennis. New to my species list.

Sexton Beetles are the great recyclers: they search out decomposing animal bodies and partially bury them by excavating beneath them. Their larvae then feed on the decomposing flesh, leaving the remnants of the buried corpse to return to the soil.

The Sexton Beetle Nicrophorus investigator

Speckled Wood butterflies are usually the first spring-emerging species that I see in any particular year, and the first generation lasts perhaps 6 weeks. Then, after a gap, their offspring emerge as a second generation:
Second generation Speckled Wood butterfly
If conditions are favourable, a third generation may appear around September.

I happened to notice today that Foxglove flowers are hairy inside:

Foxglove flowers

I can't really work out a reason for this (the just-visible orange reproductive parts are on the upper side of the tube). There would be no point in scraping pollen off onto the floor of the tube, so maybe it's just a doormat. (Late thought: the only insects that can successfully pollinate Foxgloves are those large enough to gather and transport pollen on their backs:  Bumblebees are an obvious candidate. So perhaps the hairs prevent smaller insects from stealing pollen without delivering any in return.)

Continuing my short series of grass images, this is False Oat-grass:

Flowers of False Oat-grass
Grasses do bear some serious examination: some of them are truly beautiful.

Dry nights usually mean a decent set of moths attracted to my lights at the front door. The newer energy-saving bulbs seem to attract more moths than the old tungsten filament bulbs, so it's a win-win set up.

This is the Clouded Border, which is one of the moths that looks most like a butterfly.

Clouded Border moth
The Flame Carpet has a bright orange-red central band on the wing which fades very quickly, especially if there has been any rain:
Flame Carpet moth
The Snout can be readily identified by the long mouthparts:
Snout moth
The Mottled Beauty can be separated from similar moths by the sickle-shaped leading part of the dark wing band:
Mottled Beauty
This next specimen caused me a bit of a problem - the markings look like scribbles - but it turns out to be a rather worn Double Dart, and is new to my Species list.
Double Dart moth

Tuesday, 3 July 2012

Research time again

A low-pressure weather system appears to be stuck over Ireland at the moment, so there has been plenty of rain (I blame Wimbledon). That means I have had some time to look at previous identification problems, and I have managed to identify a leaf-hopper that I found in July 2009. It's the Potato Leafhopper - Eupteryx aurata:

Potato Leafhopper - Eupteryx aurata
It's one of the few leafhoppers that have a common name, presumably because it is said to be a pest on potatoes. (It's interesting that the few fungi or insects that have been assigned 'common names' are the ones that we find most threatening. Death Cap and Destroying Angel come to mind.)

Identification new to my species index, which now stands at 1431 species.