Beautiful high pressure

A rare high-pressure weather system brought dry heat yesterday, so a lot was going on.

My first worker bumblebee (probably Bombus terrestris, but hard to be certain) of the year was gathering pollen from a half-open Dandelion:

Worker Bumblebee with phoretic mites

When I got back to the computer, I spotted the mass of mites on her back, between the wings. Phoretic mites attach themselves to a number of different insects, but do not feed on them directly: they use the insects as transport between feeding locations, such as bee nests or corpses.

I previously showed mites on this page:

http://donegal-wildlife.blogspot.ie/2008/08/phoretic-mites.html

Notice that they attach themselves in a place where the transporting insect cannot easily wipe them off, and can also choose precise locations that disguise their presence.

Field Horsetail has pale fertile shoots which precede the green sterile ones:

Fertile shoot of Field Horsetail

The cone at the top produces spores which have 4 curved 'legs' that are very responsive to humidity. As the air humidity changes, the legs expand and contract, curling and uncurling. Little hooks at the end catch on to surrounding vegetation, and the spores pull themselves around in different directions order to increase their chances of dispersal. Here's a shot of the spores that I took in 2003:

Equisetum spores at x100

As an aside, I noticed that Google Chrome has a facility to search for 'similar pictures'. The list of images for this included Chinese script, pen and ink portraits and maps.

Bilberry (local name mulberry) flowers opened over the last day or two:

Bilberry flowers

Leaves have scarcely emerged before their fungal rusts appear. This is the rust Puccinia chaerophylii on Cow Parsley:

Puccinia chaerophylli on Cow Parsley 

 

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

Recolonisation

The area I went to today was Spruce plantation for 50 years, then it was clear-felled about 10 years ago.  The original heath environment has recovered somewhat, leading to a wide diversity of wildlife where there was nothing but a black, arid desert for 50 years.

The area is rich in lichens, mosses and heathers, and the remaining stumps and logs are home to more lichens, fungi and insects.

Bilberry is just flowering now, and this flower has drops of what I presume is nectar forming on the inside:

Bilberry flower

Racomitrium mosses have a very distinctive appearance: each leaf ends in a long, twisted hair that gives the plant an overall pale colouring.

Racomitrium lanuginosum

Peltigera lichens are very leafy in appearance, although their colouring ranges from black to palest grey. This huge (40 cm.) specimen of Rabbit's Paw lichen -Peltigera membranacea - is growing on a dead log. 

Here's a close-up of one or two of the individual 'leaves' (properly called 'thalli'):

Peltigera membranacea

Equisetums (popularly known as Horsetails) are some of our most ancient plants. This immediate area has three species in very close proximity, although I do know of a nearby area with Wood Horsetail which clings onto remnants of its original woodland habitat (which presumably preceded the Spruce plantation).

Marsh Horsetail tends to grow in the fringes of wet areas:

Marsh Horsetail

Whilst Water Horsetail definitely prefers its feet to be very wet:

Water Horsetail

Field Horsetail has separate, pale, fruiting growths, which precede the green non-reproductive shoots:

Field Horsetail

Horsetails reproduce via spores which have hair-like growths attached to them. These hairs are very sensitive to humidity and they expand and contract very rapidly, enabling the spores to move through the undergrowth as if they were walking. 

This next shot is rather interesting:

Bombus bohemicus

It's Bombus bohemicus, one of the parasitic Cuckoo Bumblebees. Bombus bohemicus is parasitic on the white-tailed Bombus lucorum complex and, yet again, timing is critical here. The queen of the host species finds a place for her nest and lays her first batch of worker eggs. The cuckoo bumblebee then invades the nest and kills the original queen before laying her own eggs. The host workers then proceed to feed the cuckoo bees for the rest of the season. I watched this cuckoo bumblebee feeding on nectar and then it proceeded to remove all traces of pollen from its legs (you can see the pollen on the grass in the picture.) Since one of the primary roles that bumblebees perform is pollination, it's clear that adult cuckoo bumblebees are of no benefit to either plants or their hosts.


Another legacy of the original woodland environment is the occasional specimen of Wood Sorrel:

Wood Sorrel

Micromoths are just beginning to make their appearance for the year. This is Grapholita jungiella:

The micromoth Grapholita jungiella

These micros are very active at the moment, and you usually have to be patient enough to follow their very erratic flight in order to see them at rest after they eventually land. 

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: