Loads of Agro(myzidae)

I had a day off work today and, unbelievably, it was decidedly pleasant outside. I promptly jumped into the car and headed off for a quick change of scene. I took myself down to Portree and headed into the woods behind the Cuillin Hills Hotel in the hope of finding some dipterous leafmines and maybe the odd beetle too. 

It didn't take too long to find leafmines, the very first Holly bush I looked at added a new fly family to my 2020 Vision List

Phytomyza ilicis - the only dipteran capable of surviving mining Holly leaves

The Holly Leafminer Phytomyza ilicis is dirt common across almost the entirety of Britain. Wherever you find hollies, you'll find the mine (unless you live where I am - it's totally absent here). I saw plenty of these mines throughout the woods at Portree today, it's very much an expected species for my 2020 Pan-fly List - 'PFL' (© M. Telfer). Legend has it that Holly leaves toughen up pretty fast, quickly hardening as they age which renders them essentially inedible. Most leaf-mining species that tried to tackle Holly would find themselves being sealed into a leathery grave, one too tough for their mouthparts to handle. Yuck! Phytomyza ilicis, however, is a prodigious eater and manages to eat enough leaf tissue (and fast enough) to develop into a fully grown larva before the young Holly leaf hardens up enough to trap it within. There's a much larger Tortrix moth that also feeds on Holly leaves, but always in the soft new growth and never in the old stuff. 

Also in the woods were a few mined leaves of Creeping Buttercup. For example...

The larva is the yellow blob at the extreme bottom right corner of the mine

There are several different species of fly that mine buttercups, so attention has to be paid to the dispersal pattern of the frass and the general track of the mine itself. Helpfully, the time of year is a huge bonus too. 

Peeling back the upper epidermis of the leaf reveals the larva within

The only British species that has buttercup mining larvae active during the wintertime is Phytomyza ranunculi, a common species across Skye. 

The maggots of leaf-mining flies do not have jaws (or legs), making them instantly recognisable from other potentially similar leaf-mining larvae such as those belonging to moths, sawflies or beetles. Fly larvae have what I call a 'pick axe' for mouthparts, they use this to hack off segments of leaf tissue before consuming it. Here's a short video clip of the larva above, watch out for the black 'pick axe' cleaving its way through the green tissue

Apologies for the background noise, that was a short clip of Kyuss you were listening to, or rather I was. 

So that was Phytomyza ilicis in a Holly leaf and Phytomyza ranunculi in a buttercup leaf. What else could I find? 

A tenanted mine on Honeysuckle

There are quite a few species of fly that mine Honeysuckle, I generally find them to be a bit of a pain to separate, so usually I don't bother trying. But this is Vision 2020 and every fly needs to be nailed to species, hence I bothered.

There are several websites dedicated to leaf mines and their causers, not just dipteran, I have them all bookmarked on my laptop. The ones I visit most are:

The Leaf and Stem Mines of British Flies and Other Insects 

British Leafminers

Plant Parasites of Europe

Each of these are excellent, though there's quite an overlap of text and image usage between them. Clicking onto Lonicera (Honeysuckle) will provide a list of species utilising that host. Keys or links are provided and all you have to do is see which fits your specimen and doublecheck between sites, NBN and various other websites to make sure it all fits together neatly at a given species. Hopefully you don't have to rear your larva to adulthood, something I'm not very good at. 

The problem was, nothing quite fitted my mines (I found several). However, a little over ten years ago it was noticed that winter-active flymines were being found on Honeysuckle which didn't really conform to any known British species. Investigations were undertaken and it transpires that there is a winter generation of Chromatomyia aprilina larvae that have differently produced mines to those of the summer generations. The big clue is the colour of the larva itself

Larva is at the end of the upper left section of mine

Exposed for the world to see

Clearly it is a pale green colour, whereas all of the others in the genus are off white. So that's Chromatomyia aprilina on the list too. Good stuff.

The one fly mine that I was fully expecting to find was Chromatomyia primulae, which occurs on Primrose leaves and is another very common species. I did locate several old, vacant mines plus one tiny aborted mine, but none were tenanted. Weird. Numbers of mined Primrose leaves seem very low this year. But I'm not worried about missing it, I'm certain I'll find plenty as the year progresses.

For anybody wondering if I've even bothered looking for beetles recently, yes I have. And I found one whilst in these woods. Found in the middle of a pretty rotten Birch Polypore Fomitopsis betulina

Tiny - note the size of the lines in my palm! 

So that's my homework for the rest of tonight - trying to ascribe this beetle to the correct family. I know it's a staphylinid, but there are rather a few to work through. I suspect this will not be easy! The fact that it's about 2.2mm long doesn't help any. Maybe I could use my compound microscope..?

Edit - I THINK it's Aleocharinae. The tarsal formula appears to be 5,5,5 - certainly the mid and hind legs are 5,5 so the front legs should be too (seeing as none of them are 3,5,5 or 4,5,5). Regards the pronotal pubescence patterns, or the Pronotal Behaarungstypen, I'm not sure whether I'm seeing type II or type V. Either way it's just sitting on a card for now. One for the dim and distant future, I suspect!  

This is a great band, the drummer's wife used to work with my ex in TGI Fridays. I give you The Enemy - Aggro(myzidae) Enjoy!