A major milestone

I decided to update my Species Index with the sightings from 2013, since I calculated that I might be close to 1500 species. It turns out that I have now amassed a grand total of 1507 species on my websites, with number 1500 going to the Destroying Angel on August 27th.

The total at the end of 2012 was 1461, so I have added 46 species so far this year. Part of this number is due to the fact that I have been invited to a number of Bioblitzes this year, and I always find something new when I go to a new location, especially if the new location is on limestone. But a few are simply species that I have previously overlooked or not had the opportunity to take a photograph. The Silver-washed Fritillary from August 28th is an example of the later category.

Here's the annual graph so far:

Species 1507 is the sawfly Heterarthus aceris:

Mine of the sawfly Heterarthus aceris

This is a common miner of Sycamore (although I certainly haven't seen it before, and there are (were!) no records in the national biodiversity database). The mine is located at the bottom right of the image. The black dots on the leaf belong to the fungus Rhytisma acerinum - Sycamore Tar Spot.

Spot of bad luck

I took a quick spin round Drumboe woods and found a few things worth noting.

This is a good time of year to find mines of Ectoedemia sp. micromoths in 'green islands' in fallen Oak leaves: the leaves you want are quite easy to identify due to the green part contrasting with the brown of the fallen leaves. These micromoth larvae extend their feeding season by blocking off the chlorophyll return valves in the leaf. This ensures that a supply of food continues to be available even after the leaves have fallen from the tree. The specimen shown below had a bit of bad luck, however:

Ectoedemia micromoth mine in 'green island' in Oak leaf

The mine starts at point A (near the midrib and on a sub-vein of the leaf) and follows the sub-vein for a while before beginning its blotch mine at point B. This is all normal procedure and has so far worked well for the larva. Unfortunately, the point chosen for the blotch happens to be exactly at a place where the valve-closing has failed, and the chlorophyll is gone, making that part of the leaf useless as food. The mine has been aborted at this point, probably because the larva has starved. Leaf-miners follow some fairly complex rules when making their mines to help ensure that:

• they don't fall out of the leaf
• they end up at a part of the leaf that contains enough food for their growth and development
• the mines don't cross themselves, which would force them to encounter (and eat) their own dung

Some of the rules involve following veins, others force a change of direction after a certain amount of time; other decisions are made by the female when she lays the egg. The rules don't always work, but I find that the vast majority of mines are successfully completed. I'm guessing that in this case the rule to turn away from the sub-vein is timed and the location was just plain unlucky.

You can see a normal mine here: http://donegal-wildlife.blogspot.com/2009/10/smart-miners.html

I found a few fungi including this Clitocybe vibecena:

Clitocybe vibecena

And a very gone-over Scleroderma citrinum earthball, resembling nothing so much as a piece of orange-peel:

Scleroderma citrinum earthball

Earth-balls disperse their spores by breaking down the outer surface, enabling the spores to be wind-distributed. The outer crust of the fungus is conveniently structured with fragile fissures which make this break-down much easier.

Even dead and now-useless parts of plants can have innate beauty: this empty seedhead of Hogweed was worth photographing:

Hogweed seedhead

Sycamore leaves are covered in their tar-spot fungus Rhytisma acerinum:

Sycamore tar-spot fungus, Rhytisma acerinum

As usual, this fungus is spread by wind-born spores. Notice that most fungi try their hardest to maximise the area available for spore production: the surface of the fungus is wrinkled and domed.

We have had solid rain for the last two weeks and I haven't seen a single moth in that time. The last night, in pouring rain, a single specimen of Red Sword-grass came to light. The Red Sword-grass hibernates as an adult, so something must have stirred this one from its hiding place.

Red Sword-grass

 Red Sword-grass has a mostly western and northern distribution and is found mostly near bogs or heaths.