Friday 26 September 2014

Catching up

Our unexpected spell of dry weather has continued, and has most certainly delayed the usual glut of fungi that would normally appear at this time of year. Last week, during the practical photography session on a macro course, we encountered dozens of mushrooms that were completely dried up, with the spores lying underneath them on the ground:

Dried fungi with spores underneath and on the cap

Spores are usually wind-borne, but these have simply dropped down onto the grass due to the complete calm. The actual fungi shouldn't suffer, since they are deeply buried inside wood or soil, and persist for years, but there will be little reproduction this year. Note that the caps are also covered in spores. Most spores are produced by the gills underneath, but some species are also able to produce spores via the upper surface of the cap and that looks to be what has happened here.

During a school trip this week, one of the pupils brought me a dead branch with fruitbodies of Chlorociboria aeruginascens

Chlorociboria aeruginascens on dead Oak
This fungus lives on dead Oak and Beech, and isn't too rare, but the fruitbodies seem to appear very rarely; this is the first time I have photographed them. Individual fruitbodies are around 3 - 5 mm. across the cap.

Now that I have the literature on spiders and harvestmen, I'm looking at them much more closely. This is the harvestman Leiobunum blackwalli:

Leiobunum blackwalli (female)

Leiobunum blackwalli (female)
Harvestmen don't make webs, but sit on or under leaves waiting for some prey to walk past. I love the way the white-lined eyes are up on stalks (called a 'turret').

New to my Species List.
  
In 2007 I found a gall on Oak which puzzled me:


Individual galls are secured by flaps of tissue on veins of the leaf, but are able to detach and fall to the ground. It didn't appear in references, and I couldn't get a name for it despite hours of searching. The new edition of Redfern and Shirley says it's very common, but I hadn't seen it before, and I haven't seen it since. It's made by the Cynipid wasp Neuroterus anthracinus

New to my Species List.

Most leaf miners stick to a very small set of plants, sometimes just one species, but some are a little more flexible and use a number of plants. This can make identifications tricky, since their appearance can be quite different on different hosts. I struggled a little with this mine of Agromyza idaeiana, which I often find on Raspberry or Meadowsweet, but this specimen was on Bramble:

The leaf miner Agromyza idaeiana on Bramble
The blotch at the end of the mine is much wider than I usually see, since it isn't constrained between veins like it is on the other plants.

Thursday 11 September 2014

Sun!

This week has been a bit of a surprise: mist in the early morning followed by absolutely clear blue skies all day. Quite delightful, really.

I have been examining my local Hawthorns for miners and came up with this rather interesting specimen:

Stigmella perpygmaeella mine on Hawthorn

It's the mine of the micromoth Stigmella perpygmaeella, which is new to my species list. At point A (the head of the mine) we can see the miner (yellow larva with oval head). But at point B we can see another, different, larva. This second larva has the look of a hymenopteran about it (round shoulders, tapering body) so it will be either a sawfly larva or a wasp larva of some sort. It is clearly heading towards the miner, so it looks like we have a predatory larva in the mine. I knew that miners could be parasitised by Braconid or Chalcid wasps, but this is an entirely new relationship. More research....

While I was working the Hawthorn, I found a few nymphs of the Hawthorn Shieldbug:

Final instar nymph of Hawthorn Shieldbug
This is the fifth and final stage of the nymph: at the next metamorphosis it will be the adult.

Capitalising on the good light, I went up to the local heath to see what I could find. Devils-bit Scabious is one of the latest plants to flower, and the path was lined in purple.

First to catch my eye was this pale pink variant:

Pink Devils-bit Scabious
I have seen this sport before, but it seemed there more around than usual this year. It looks like the pale colour doesn't put off the pollinators.

This shot shows another oddity which I see from time to time:

Viviparous flower of Devils-bit Scabious
The bud at the top is a viviparous flower growing out of the flower below it. It isn't a branch, because the stem arises from inside the lower flower. Not quite sure why this happens.

Here's a shot of the hoverfly Episyrphus balteatus on a normal flower:

Episyrphus balteatus on Devils-bit Scabious
I noticed this cluster of Russulas from the path side and immediately thought "Russula mairei", which is common everywhere around here, but then I realised there were no Beeches around:

Russula emetica - The Sickener
The trees above are Fir and Pine and the mushrooms are growing through Sphagnum. This is classic habitat for Russula emetica, which I have been hunting for perhaps 10 years. This habitat is perfect for it, so I wonder why it has taken so long to get here. New to my species list, at last.

Russula emetica - The Sickener
Russula mairei is known as the Beechwood Sickener, but Russula emetica is known as The Sickener, as you might guess from its specific name.