Thursday, 21 April 2011

Limestone

I live in an area of highly acid soil, so I'm always keen to visit limestone areas. Soil type largely governs which plants can be found in a particular area, and different plants support different insects, so I always expect to find something new or different on these trips. Lough Erne is also much closer to sea level, so it's probably 7-10 days earlier than my local area.

My local violet is the Common Dog Violet - Viola riviniana, but this area has both riviniana and Viola reichenbachiana. The most obvious differences are the narrower flower and more pointed leaves: 

Viola reichenbachiana

And the dark, straight spur behind the flower:
Viola reichenbachiana spur
Both violets were growing on a verge accompanied by Ground Ivy:
Ground Ivy

Bluebells were just starting to open:

And this Dock Leaf Beetle - Gastrophysa viridula - was either touring or lost: they are rarely seen far from Dock leaves.


I spotted my first Ichneumonid of the year. The size suggests that these will be looking for either large flies or small moths:


This flower is Cardamine pratensis, which is the main foodplant of the Orange Tip butterfly, but is also used by the Green-veined White:


The minute moth is Micropteryx calthella, which is associated almost exclusively with Buttercups in my area, but it clearly uses other nectar sources when they are available. I don't expect to see Micropteryx calthella for perhaps another 3 weeks on my patch (the buttercups aren't even in bud yet).

I was delighted to find a new hoverfly species on the same verge. This is Epistrophe eligans, one of the earlier species to emerge:

 Male Epistrophe eligans

Another plant that I only ever see on limestone is the Cuckoo Pint, a most wonderful member of the Arum family:
Cuckoo Pint

No matter where I find Holly, I always find its leaf miner, Phytomyza ilicis. I was always curious that only one species of miner lives in Holly leaves because it seems such a safe place for an insect to live. It turns out that Holly heals very quickly when damaged, and the plant considers the mine to be a wound. Phytomyza ilicis is the only miner that moves quickly enough to keep ahead of the healing process:

Phytomyza ilicis on Holly

Moth flies are a mysterious group of flies that run around on plant leaves like little planes trying to take off. The larvae live in cesspits, drains and compost heaps:
Moth Fly
Lough Erne is a large expanse of water, so I usually expect to find some water-based species.

Alder Fly larvae are aquatic, and I only ever find the adults near rivers, ponds or lakes. The Alder Fly Sialis lutaria has to be one of the least aptly named of all species. It isn't a fly (it has 4 wings and is related to lacewings) and it has no association with Alder:
Alder Fly Sialis lutaria

Talking of aquatic species, I spotted this Coot sitting on her nest:

Coot

A couple of fungi to finish.

Last year I found a rather rare fungal infection - Taphrina crataegi - on Hawthorn. The leaves are only just open, and this bush was already infected:

Taphrina crataegi on Hawthorn
This appears to be the first record for Northern Ireland.

April 23rd is St. George's day, and St. George's mushroom - Tricholoma gambosum - is traditionally found around this date:

St. George's mushroom - Tricholoma gambosum

The spores are minute, around 5 x 3 microns:

6 comments:

Gill said...

Lovely - I'm particularly taken by that little moth fly.

Is the little dot at 1o'c on the milkmaid (Cardamine) flower in fact an egg?

Stuart said...

Gill: The little yellow dot is just a bit of pollen (or pollen-coloured fly dung). Orange Tips lay a single orange egg behind the flower, and GVW lay green eggs on the leaves and stems.

OT's are also very picky about which plants to use. They only lay on plants which are on a south or southwest-facing bank.

Caroline Gill said...

Thank you, Stuart, for your info on the Dock Leaf beetle ... I have a couple of pix of this species to post ... perhaps tomorrow.

What a fruitful expedition!

Caroline Gill said...

Just posted my DLB photo ... here. Thank you for helping me ID the creature!

Stuart said...

Caroline: yup....that's the beastie. Check soon for clusters of bright yellow eggs on the underside of the leaf and then for black larvae for a couple of weeks as they destroy the leaves. The entire lifecycle is around 33 days if memory serves me right.

lmcsteelandcladding said...

Dora says

Great photos Stuart - What a beautiful day and a job very well done-Thanks a million for all your assistance.