Wednesday, 21 October 2009

Autumnal moths

Considering that most insects need heat before they can move, it never ceases to amaze me that some species don't emerge until it's almost time for a frost. This is the Small Autumnal Moth - Epirrita filigrammaria.

And this is the November Moth - Epirrita dilutata, in a colour form that makes it paler than the virtually indistinguishable Pale November Moth.

I suppose it means that there is less competition for food, but it seems a risky strategy.

Tuesday, 20 October 2009

Lichens from Ards

Lobaria pulmonaria is a lichen in which the photobiont (aka 'the prisoner') is a nitrogen fixer and they are a major source of nitrogen for forest plants, including the trees they grow on. This is the only location where I have found the species, although I understand it is more frequent in southwest Ireland.

Lobaria virens is even scarcer in Ards than its close relative: in fact I know of only one tree which hosts it.

You have to go the oldest and cleanest forests to find these lichens: they are extremely sensitive to disturbance and pollution.

Sunday, 18 October 2009

Extreme rarity

I immediately knew that I had never seen this mushroom either in the field or in any literature. The cap was covered in a brown powder, and the stipe (stem) had a distinctly bitter almond smell. A search through all my books revealed no close match, so the internet was the next port of call. I had almost chosen Rozites caperatus as the likely candidate when I was very lucky to find a comment on a swiss website that mentioned that some Rozites could be mistaken for Phaeolepiota aurea. A quick check confirmed that this extremely rare mushroom was the correct identification. It's a nettle associate, documented in european literature, but not in English. The almond smell is due to the presence of cyanide compounds, but strangely I was the only person out of four who could detect it, and for me it was so strong I recoiled from the smell. There are a few Irish records. Provisional red data list.

Some fungi are successional, depending on other fungi to have been present before they can fruit. This succession can take decades to occur, and there may be several links in the chain, so some rare fungi are only found in our oldest forests, and they might not make fruitbodies every year. Ards forest in west Donegal is very special: it's an ancient forest on the first landfall from the atlantic, so it's old and very clean. It has many rare fungi and is home to some very rare lichens that need extremely clean air, so it's a wonderful place to visit.

Phellodon melaleucus is one of the rarest fungi, and most mycologists will never see it in a lifetime. I've been privileged to see it for a few years now, always in exactly the same location. It smells strongly of fenugreek, especially when dry.

Right next to the Phellodon, I found a small stand of Clavaria vermicularis:

I feel priviledged to have seen these three species in the space of a few days.

Tuesday, 13 October 2009

Smart Miners

Leaf miners on deciduous trees have a limited season for their development: they need to feed while leaves are green. That means they are usually only found between April and September/October. In autumn, trees withdraw the chlorophyll from the leaves for reuse in the next next year, turning them brown before they drop to the ground to become composted.

Some of the Ectoedemia micromoths have found a way to block the return valves, creating small 'islands' of chlorophyll in the leaves, even after they have fallen, thereby extending the length of their season. This Oak leaf has a couple of 'islands' containing mines of Ectoedemia heringi:

Bright, white mines with widely dispersed frass (dung) are usually dipterous. These are the mines of at least 14 specimens of Phytomyza spondylii on Hogweed.

Notice the crescent-shaped exit holes where the larva has left the leaf to pupate:

Another new miner for me: the micromoth Caloptilia syringella on Ash. I suspect this one is usually too high in the tree for me to see it, but this branch had broken in high wind.

A couple of moss shots. The capsules of Thuidium tamariscinum:

And a shot of Hookeria lucens, showing how the overlapping leaves retain water: one of a few techniques used by mosses to keep wet.

Monday, 12 October 2009

Top Secret

Now I have to keep the location of my garden secret. This is Psilocybe semilanceata - the 'magic mushroom', and my lawn is covered with them.

It is illegal to have these fungi in your posession.

Tuesday, 6 October 2009

Anatomy of an identification

This moth came to light on Sunday night:

It was noticeably grey under the light, and I noticed the 'round' shoulders, so my first thought was 'an early specimen of Epirrita sp.' As soon as I got a look at the flash shot, however, I saw it was actually green, so my thoughts transferred to 'worn July high-flyer'. But it's far too late for that (and the pattern's wrong, anyway). So I began to trawl the references and came up with a green specimen of Yellow-barred Brindle, which would also be a bit late. So I sent the picture off for analysis. The recipient came up with two options :Red-green Carpet or Autumn-green Carpet, but neither seemed to fit properly, so it was sent to another person who has experience of these species in Ulster. The consensus comes down to Autumn-green Carpet - Chloroclysta miata - a local species which is usually found near old woodland and bog, and is new to me.

Sunday, 4 October 2009

Local Fungi

With fungi, you sometimes just have to stare at them blankly for a while and then a picture suddenly forms in your mind and a possible identification suggests itself. I went through and rejected quite a few possibilities for this one before I hit on Cortinarius. When I got back to the books it was clearly one of the Dermocybe group, and the yellow gills indicate that it's Cortinarius croceifolius (now Cortinarius malicorius) - a Salix associate, which would fit perfectly.

The dotted margin for this one points us towards Hypholoma marginatum:

This little group of Collybia dryophila caught my eye:

Thursday, 1 October 2009

My garden

The excellent Lawyer's Wig - Coprinus comatus - is a rather common mushroom: I find it on lawns, verges and rough wasteland.
It's edible, although it tends to take on the flavour of other cooking ingredients, rather than adding flavour of its own.

The other day I mused about dependent species following their host. This concept is very clearly illustrated by Apanteles glomeratus, a Braconid wasp that is parasitic on some of the 'white' butterflies. The Large White and Small White butterflies became very scarce on my local patch, presumably because people had stopped growing their own brassicas: the Large White wasn't recorded in our 10k square for 10 years. However, as soon as I started growing Broccoli 2 years ago, both species were recorded on my vegetable patch.

When they're ready to pupate, they crawl up to the eaves of buildings and overwinter in their chrysalis. They start by making a web on the upper surface, and this is the instant that disaster can strike. The larvae of Apanteles glomeratus live inside the caterpillar, eating non-essential fat deposits, using the caterpillar as a mobile food producer. The instant the web is spun, however, they burst through the larval skin and pupate for themselves. The yellow cocoons are shown below:

Approximately 60% of this year's Large White larvae appear to be parasitised, which falls within normal expectations.

So although the host was missing for 10 years, the parasite is present only two years after the host returned.