Confessions of a Pan-species Lister...: Images of Smut

The bin lorries can't get to where I live, so I need to walk my rubbish and recycling down to the pier, a walk of maybe 300 metres. The track to the pier passes beneath some mature Beech trees, alongside a low stone wall, past some derelict buildings and ends at the tarmac road by the pier. It's all a bit overgrown and untidy, meaning there's always something different that catches my eye whenever I pass through.

Today I spent a short while exploring the walls of the derelict buildings, basically just taking pics of the various plant species that have colonised the exposed stonework and cracked render. Some were entirely expected, Maidenhair Spleenwort for example is everywhere up here, as is Fuchsia and Buddleja. But I found a couple of less expected species too.

A couple of the derelict buildings just upslope from the pier

And here are a selection of the plants I found growing out of the walls

Butterfly Bush Buddleja davidii

A young Prickly Sow-thistle Sonchus asper

Common Ragwort Jacobaea vulgaris

Hart's-tongue Fern Asplenium scolopendrium

Maidenhair Fern Asplenium trichomanes is abundant on most old mortared walls up here

Short-fruited Willowherb Epilobium obscurum with another sow-thistle

Fuchsia Fuchsia magellanica is another common species up here

Presumably Red Fescue Festuca rubra. It's an abundant grass here

Wall Lettuce Mycelis muralis. A really good plant on Skye, known only from the Broadford area!

Ribwort Plantain Plantago lanceolata

Wilson's Honeysuckle Lonicera nitida. Not sure I've ever seen this growing out of a wall before!

Common Figwort Scrophularia nodosa. Can't honestly say I expected to find this on a wall

Entire-leaved Cotoneaster Cotoneaster integrifolius which can become a bit of a menace

An Ash Fraxinus excelsior sapling!

Leaving the buildings, I headed back to the house quite happy with the Wall Lettuce and Wilson's Honeysuckle records. On a low wall I spied a large clump of Intermediate Polypody Polypodium interjectum and, more out of habit than expectation, had a quick peer on the underside for signs of Psychoides damage. Well...

Do you see them yet?

I checked a few more fronds and soon found this

Aah, now you see them!

Now that's what I call a pretty heavy Psychoides infestation! I took a frond back to my microscope to confirm which of the two Psychoides species I had found, though the untidy mess (and my previous Skye records) already strongly hinted at the species involved.

Just so we're all on the same page here, there are two species of micromoths in the genus Psychoides that occur in Britain. They both lay eggs on various species of fern and the newly-hatched larva starts off by mining the leaf tissue before emerging onto the underside of the frond whereupon it uses silk to bind together fragments of the fern's spore-bearing sori into a 'tent', under which it hides as it feeds. One species constructs rather messy 'tents' and the other makes nice neat ones, which it moves around in as it feeds. The two species can be reliably told apart from each other as larvae by checking the colour of the prothoracic plate (which sits immediately behind the head) and anal plate (at the 'tail' end).

P.filicivora has a pale to mid-brown head capsule, a transparent prothoracic plate (allowing the brown head capsule to be seen through it) and a pale anal plate the same colour as the body segments.

P.verhuella has a blackish head capsule and prothoracic plate, and the anal plate is also blackish, contrasting with the pale body segments.

Time to see who we have...

Brown head capsule is readily visible through the covering prothoracic plate, no dark anal plate.

This is Psychoides filicivora, the one with the messy 'tent' and the only one of the two species so far known to occur here on Skye. Here's a handy comparison pic I just nabbed off Wikipedia, of all places

I took lots of pics by pointing my camera down the barrel of my microscope. Quality is a bit hit and miss when using this technique (it is for me, at least) but I was pleased with this short video clip. It shows a larva, which I'd rudely unearthed from below its tent, in the process of putting together a fresh tent. I should probably stop calling it a tent, maybe retreat would be a better word. Anyway, if you view this on a big screen you can just about see the silk being produced from the mouthparts and used to bind loose fragments of sorus together!