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 

 

Heat at last

We had a couple of warm days and suddenly everything is moving.

Solitary bees dig private tunnels in soil where they lay their own eggs and bring back pollen to a store which will feed the larvae when they hatch. These nests are often grouped in 'aggregations' of tunnels where the situation is favourable, but each individual tunnel remains self-sufficient. The largest family is Andrena, where the females can often resemble small bumblebees. My favourite is Andrena cineraria, where the female appears to be wearing a Barbarians rugby jersey:

Female Andrena cineraria gathering pollen

Once the pollen has been gathered, the female will seal the tunnel and the larvae will hatch, eat the pollen, pupate and then hibernate until next spring. The species with the shortest season is Andrena clarkella, which feeds exclusively on Willow pollen, and most nests will already be sealed: this is a bee that can be seen for perhaps 50-60 days each year.

Staying with Dandelions, I spotted this 14-spot ladybird in the precise centre of one. this will give a good idea of scale:

14-spot ladybird on Dandelion

And an intriguing shot of an aberrant Dandelion:

Aberrant Dandelion

Dandelions belong to the Compositae, which includes Thistles, Daisies, Knapweed, etc. Each 'flower' is actually a composite collection of individual flowers, some of which are Ray florets (the outer ones), and an inner group of Disc florets. This specimen appears to have dispensed not only with disc florets, but also with the reproductive parts of the ray florets. I rather suspect that this is a genetic experiment that is doomed to be unfit for survival. All flowers on the same plant were identical.

The following shot shows just how late this year has become. I normally see Greater Stitchwort in late March, but this specimen is at least 6 weeks behind the usual date:

Greater Stitchwort

Lady's Mantle has a habit of not being there one day, and then being fully opened the next. When I was down taking a shot of the lovely folding leaves, I noticed a couple of other leaves waiting to be discovered:

a) Lady's Mantle b) Meadowsweet c) Meadow Buttercup

Flowers of the Lady's Mantle are at the lower left.

I wasn't expecting to see too many fungi at this time of year, but I found a couple of very old Polyporus badius on dead Snowberry:

Polyporus badius

And a couple of specimens of a Psathyrella which I think is Psathyrella spadiceogrisea. I'll do some microscopic work on these once the spores have been gathered:

Psathyrella cf. spadiceogrisea

Yesterday, I saw 3 species of butterfly in the garden. There were perhaps half a dozen Small tortoiseshells, a single Green-veined White and late on, a single Speckled Wood.

Small Tortoiseshell butterfly

The Green-veined White and Speckled Wood are this year's first butterflies, whereas the Small Tortoiseshells are actually last year's autumn brood which have emerged from hibernation. Orange Tip has to be next, since the Cardamine is out.

Bilberry has flowered, so perhaps we might see a Green Hairstreak or two in the next week or so:

Bilberry flowers

I was a little surprised to find Field Woodrush on the patch. I normally see Heath Woodrush, and maybe I have been ignoring these smaller specimens. One major clue to identification is the pale 'blob' at the end of each leaf:

Field Woodrush - Luzula campestris

Lastly for today, a few specimens of Green Alkanet were spotted on a verge at the side of a remote road:

Green Alkanet

These are garden escapes, but I cannot imagine anyone taking their garden refuse for such a distance in order to dump it. Maybe bird-sown.

Sun's back

After a couple of weeks of rain, sleet and hail, things have warmed up again. Various Solitary Bees have been nectaring, and I spotted my favourite bee - Andrena cineraria - as she gathered pollen from a Dandelion:

The solitary bee Andrena cineraria

I always think they look like they're wearing Barbarians rugby jerseys. Here's a side shot:

Andrena cineraria

Andrenas (and other families of Solitary Bees) lay eggs in their own nesting tunnels, and although they might form communal 'villages' of individual nests, the female feeds only her own larvae with pollen. Nomada sp. Cuckoo Bees are ever present near the nests, hoping to get an opportunity to nip in and steal the pollen store when the female is out foraging.

Bilberry (locally called Mulberry) has flowered:

Bilberry flowers

Bilberry is a vital food source for a number of insects, most notably the Green Hairstreak butterfly. I like the way the unopened flower can sometimes contain water droplets:

Unopened Bilberry flowers

I have a number of different species of Fumitory on my patch. This is Common Fumitory, which gets its name from the grey-green foliage which can look a little smoky:

Common Fumitory

The local Willows are all in full leaf now, so it's time for the various Willow Leaf Beetles (Chrysomelids) to appear. This is Lochmaea caprea, which I happened to spot as it sunbathed on my recycling bin (which happens to be right under a Willow):

Willow Leaf Beetle - Lochmaea caprea

The Willow leaves will soon be showing the attentions of the beetle larvae as they eat off the top surface of the leaves.


I also spotted a few Bibio sp. (St. Marks Flies), which usually emerge around St. Mark's day (April 25th), so we're still running slightly ahead of schedule this year despite the last two cold weeks.

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. 

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:

Lichens - fungi that have learned the art of gardening

Lichens are a familiar sight on walls and trees, especially in areas free of pollution. They are the pioneers of the natural world, living in often hostile conditions, and converting stone and wood into soil. The following image is a wonderful example of this pioneering process:

The fencepost which forms the basis of the eco-system we see in the image was put in position around 50 years ago. A series of lichens would have appeared very quickly in succession, each one preparing the post for the next. As the lichens died they would leave dead fungal matter, dead algae and rotted wood. Sooner or later a moss spore will have found this mixture suitable as a substrate and the moss began to live (and die) there. This decomposed vegetation eventually provided sufficient soil for the Bilberry to take root. So in a very short number of years, we have a sterile fencepost being turned into a habitat suitable for fruiting plants. It should be noted that the post still hosts a number of lichens and mosses in addition to the Bilberry. The process on stone takes slightly longer.

If you read any literature on lichens, you will be told in no uncertain terms that "lichens are a symbiotic relationship between a fungus and one or more algae or cyanobacterium". Whilst it's true that each lichen contains a fungus and one or more algae, with the combination being named after the fungal partner, I think the relationship is rather one-sided:

• Firstly, the algal partner can - and often does - survive on its own, whereas the fungus cannot. (Typical examples are Trebouxia and Nostoc, both of which I have found growing freely in a number of places.)
• Secondly, the reproductive system of a lichen is either purely fungal, or a combination of a fungal component with a captive parcel of algae.

We need to look at what each partner adds to the relationship. Clearly, the alga produces energy from sunlight - something the fungus cannot do, so the fungus is the major beneficiary here. The fungus provides the physical structure of the lichen - basically a house for the alga, which is constrained by the lichen, and is only able to reproduce within the confines of that structure, and is unable to free any part of itself as independent offspring. It seems to me that the alga is trapped and imprisoned by the fungus largely for the benefit of the fungus. Hardly a fully symbiotic relationship.

The following image shows the fruitbodies of a lichen that clearly demonstrates the fungal nature of the reproductive system. Lichenomphalia umbelliferae is a lichen that grows in association with mosses. The fruitbodies are about 10 mm across the cap.


The actual situation is much more complex, of course, with some fungi that can be part-time or opportunistic lichens. A couple of years ago, I took this picture of Boletus erythropus with a golfball-sized lump of algae on its stipe. Notice the lichen-like appearance of the surface of the lump.
This 'skill' of harnessing the photosynthetic properties of algae must be deeply embedded in fungi.