Sieving in the Snow

Last night we enjoyed a decent snowfall and I was keen to head into the hills to enjoy it. As of tomorrow I'm back on duty, so this will be my last outing in daylight until next weekend. 

The view up Glen Conon is stunning

I couldn't see myself making too much use of my net today, the only things I saw in flight were birds rather than insects, so I headed into the woods to retrieve my cunningly hidden sieve and tray. 

Still exactly where I'd left them, thankfully  

 

Now I know what you're wondering - what the heck was I intending to sieve with all that snow on the ground? Well it wasn't deep snow, just a couple of inches worth beneath the trees. And the tussocks here grow taller than that. 

et voilà, a tussock!

I unearthed about half of this tussock, teased the base apart into smaller pieces and shook the whole lot through the sieve. I have to say, the pickings were rather slim - a couple of springtails, a small sphaerocerid, the beetle Anotylus rugosus and a couple of very small millipedes. Not exactly the bountiful reward I was hoping for! I sieved a couple of nearby tussocks with similar results when I suddenly realised I was no longer alone.

A man I've never seen before came wandering down the hill and clambered the fence about 40ft from where I stood motionless, nose in my tray, pooter in my mouth. Then he took his coat off and yelled "Good morning world!" through the woods. "What's that, mate?" I asked, causing him to spin around in startlement. "Oh aye, er yeah..." he said, before pulling at his jumper. Was he about to strip naked right in front of me, I wondered? And there I was thinking that I was the biggest weirdo in the woods. Luckily he soon finished rearranging himself and stood there facing into the trees ahead of us. I figured it was a good time to quit the tussocks and head off in the opposite direction, which I did with purposeful strides, trying my best to look impressive and definitely not the kind of person you'd want to mess with. 

There's a short section through the woods where you're effectively pinched between the fence line and a long drop into the river far below. At its narrowest point the woodland floor here is only about twenty feet wide. I walked through this narrow squeeze and continued ahead into the woods. After a hundred metres or so, I circled back to view the narrow point from about fifty metres dowhill. I then waited to see whether the weirdo was following my footprints. Eventually I figured not and resumed my tussocking. In all the times I've been in these woods, this is just the third occasion I've ever seen another soul up here, and the first time I didn't recognise the person. Happily, the tussocks were rather more productive beneath these larger trees and I even found a few handfuls of dry leaflitter amongst the roots of a huge Sycamore. The dry leaves in particular revealed lots of invertebrates for me to pick through.

Stenus sp. - that's one I don't have to worry about this year! 

Othius punctulatus - another one I don't have to worry about this year

This bizarre thing is actually a fly larva

I didn't retain this larva, it was still active and could be months away from pupating. It would only die if I tried to rear it through, so I put it back in the leaf litter. The diagnostic 'lateral extensions' tell me that this belongs to the genus Fannia, which are the Lesser Houseflies. As adults, these flies often fly around my face when I'm mowing the grounds, occasionally even landing on my nose and lips! Quite annoying really, I'm very glad they don't bite. With snow laying all around me, that seems like a dim and distant memory, but I know they'll be back in the summer, waiting for me beneath the trees on the back lawns. 

Nemastoma bimaculatum - I had eight of these in the tray at one point!

I think I found more of these black harvestmen today than I ordinarily find in a month. Clearly they like to use piles of leaves at the base of trees as an overwintering site. I also found a few money spiders, but they went straight up the pooter and into alcohol so no pics of those, I'm afraid. 

I stashed my sieve and tray in a different part of the woods, I'm worried that the weird fella will be back again and I don't want him messing around with them. (Ha, he probably has his own blog and is currently writing about the weirdo he encountered today, staring into a cat litter tray with tubes hanging out of his mouth...) 

Back indoors I managed to identify the three sphaerocerids I collected as Ischiolepta denticulata, Leptocera fontinalis and Lotophila atra, the latter being my second for the site this month and the others being lifers for me. They are all common species, often associated with tussocks and small mammal runs in woodland, but according to the NBN only L.atra is already known from Skye.

This is a male Ischiolepta denticulata with its amazing scutellar teeth and warty-looking surface

Being a male, it has a tiny tubercle (arrowed) near the base of the hind femur. Not easy to see!

But it was the same old story with the spiders I collected, either subadult males or adult Tenuiphantes zimmermanni. Yet again. Supposedly you can often find several species of Tenuiphantes together, but Uig Wood seems to be bucking that trend. One was a particularly darkly-abdomened individual and I felt confident it would be a different species. Nope, still a flippin' zimmermanni! 

The palps don't lie

And here's a more typically patterned male Tenuiphantes zimmermanni

I do hope I'm not overlooking other species amongst the zimmermanni I'm finding. Trying to translate the image in the book to what you're looking at in real life is not as easy as you might think. Spider palps are complicated 3D structures, stunningly so in fact, but that makes them difficult to accurately reproduce on paper. Hence the 2D figures in the books, magnificent though they are, inevitably fail to adequately convey the various different parts that you see whilst looking down the barrels of a microscope. So saying, I'm fairly certain I haven't misidentified any tenuis yet. He says...

This is a female Lepthyphantes minutus that I found in the laundry shed a couple of days back

I suspected that's what it was straight away, due to the heavily annulated orange legs and mass of leg spines. But I needed to check the epigyne to confirm that ID. Oh boy, what an epigyne it is too! All attempts at a 'head-on' shot failed, it projects outwards too much for the camera to stack properly. So here's a profile view of it instead

In my head, I see epigynes as being rather flat objects laying against the 'belly' of the spider. But this thing juts out almost like a weird proboscis! Happily it matches Lepthyphantes minutus perfectly, so that's another bit of learning done and confirmed. 

Ok, so that's my adventuring outside of the hotel grounds done for another week. Not sure what the weather is doing over the next few days, but I'll be checking the walls and laundry shed after dark in search of who knows what. I may have to get some bait traps going at some point soon too, especially now that I know Sylvicola are attracted to them. Then again, if the snow keeps up it may not be worth it. I won't know if I don't try! 

Number of people encountered during this outing: one. 

Only 50 Weeks Remaining!

Apologies for the slightly dramatic title of this post, I was going to call it 'Mid-January Update' but that seemed a bit kind of lame. Anyway, here's the mid-January update to my Spiders and Flies Challenge. 

In a nutshell, my efforts to find spiders and flies this past fortnight have not been anywhere near as intense as they should have been. The weather has reverted to the grey, wet and windy conditions that are typical for this time of year and my enthusiasm for wandering cold, wet woodland has yet to take off (as can be seen with a quick glance at the dates below...)

The spiders

 

And the flies

I hope you can read those, clicking on them will enlarge the image. Essentially they show that I haven't added much of late and that already I'm falling behind with my iRecord submissions. I'm finding the Uig Wood spiders mildly frustrating, because they seem to consist of a very limited number of species. Tenuiphantes zimmermanni is the commonest denizen of tussocks and mosses on the woodland floor and I'm finding lots of female specimens, though strangely only a couple of males so far. But I have yet to find Tenuiphantes tenuis which should definitely be here. This is about the best image I could manage of the left pedipalp of a male Tenuiphantes zimmermanni. The entire spider is around 3mm in length, hence you'll appreciate that the pedipalp itself is somewhat miniscule.

Below is what a proper picture of the pedipalp looks like. Note the red arrow pointing at a small 'tooth', this 'tooth' being an important feature which helps differentiate zimmermanni from tenuis. You can see it on the photo above too, though in my image you're viewing the palp obliquely from below, so it doesn't quite match the image below. Damned fiddly things to orientate correctly, particularly when the spider is suspended in alcohol and keeps falling onto its back!

See original at Tenuiphantes zimmermanni – Wiki der Arachnologischen Gesellschaft e. V. (arages.de)

The other spiders I'm finding with regularity are from the genus Metellina. These also happen to be the largest spiders I'm finding in Uig Wood, what I'd call a proper macro-spider as opposed to the linyphilids which are mostly micro-spiders, though some of them do approach macro size (I've coined those phrases myself, you quite rightly won't find them written in the texts).

This 'covering your face' pose appears to be typical for Metellina spiders after they've crash landed into the tray. I guess it's a good cryptic pose to adopt, certainly I've overlooked them several times when they are in this tucked-in position. It's only when they burst into their lumbering escape mode that they become really obvious. 

Female Metellina merianae in lumbering escape mode

Sadly for her, she didn't lumber quite fast enough and I popped her into alcohol for subsequent examination. There are several species of Metellina on Skye and I intend to keep track of which ones I see and where. Though currently, thanks to the latest lockdown, the 'where' is always going to be somewhere around Uig. As a brief aside, many birders have latched on to an idea that, though not new, is currently proving popular - birding within a five mile radius of home. It offers more flexibility than the #BWKM0 that proved so popular in the first national lockdown, yet fulfils the 'stay local' criteria that we're being told to adhere to. 

I had a quick think about this. Currently, at least, the covid threat is pretty low on Skye. For myself, I think the opportunities offered by this 5MR idea far outweigh the risks. I plotted a map, just to see what was on offer.

My new Patch area - a circle ten miles wide with 2/3 of it being (rather helpfully) on land

I shall blog about this in depth elsewhere, but I like that it provides me the opportunity to add extra dots to the species maps. I must keep the batteries in my GPS fresh and remember to pack my OS map with me whenever I head out. 

Back to the spiders. I eventually added a second Metellina species to the tally. This was a male and immediately stood out as being different due to the pale orange wash across the upperside of the abdomen. I could see that it was an adult so popped it straight into the alcohol pot and checked it out once back indoors.

Note the obviously forked paracymbium (arrowed)

The forked tip and overall shortness of the paracymbium allows us to identify this as an adult male Metellina mengei. For comparison, below is the pedipalp of Metellina merianae, which is the one I usually find here.

Not in focus, but you can see it is very long and upright, and strongly bent after the middle

The other recent addition to the spider tally is one that I immediately recognised, having already encountered it last year. The long spinnerets and overall rather chunky look are very distinctive. This is Cryphoeca silvicola, a subadult male (note the pedipalps aren't fully developed) but still readily recognisable, despite it being a mere 2mm in length. It's a common spider, so I'm sure I shall bump into one again soon.

Cryphoeca silvicola - subadult male

Right - enough of the spiders, let's move on to the flies. Despite having only recorded seven species so far this year, I managed three lifers in the first half of January. Two of these were sphaerocerids (Lesser Dungflies) that I sieved from grass tussocks and the third was a gall midge, found after a targeted search the day after learning of its existence. This is a truly abysmal pic of a Downy Birch catkin that has had most of the seeds removed, revealing the swollen and galled seeds glued to the central spindle. The species involved is Semudobia skuhravae and is one of three in the genus to form galls in birch catkins. I haven't found the other two yet, but I will. Finding catkins here isn't as easy as you'd expect, I searched maybe twenty trees and found only two! I shall have to find some birches in a more sheltered spot, hopefully they will have retained their catkins for longer. 

Here's a very nice picture of the same thing, taken by a professional on the Bladmineerders site

Being the curious type, I opened up one of the galls just to double-check the inhabitant was indeed dipterous. A tiny orange grub blinked up at me, then retreated to the bottom of its gall. Yep, that's the badger alright! 

Semudobia skuhravae grub in its gall

There are ten or so galls on what's left of the two catkins I collected, plus the opened gall with the grub inside, all currently sat on my windowsill. I'm hoping they will successfully emerge in the spring so I can see what they look like as adults too. I did notice a couple of black pupae in the catkin, I think these must be parasitic wasps that have already killed their host. With luck, this means the rest are unparasitised. We shall see.

Tomorrow I have a WeBS count to undertake, which means I'll be using my car for the first time in a while. I think I shall head further into my 5MR zone, see what I can find elsewhere. I've stashed my sieve and tray under a fallen tree in Uig Wood - they are too big to fit into my rucksack and I simply couldn't be bothered with lugging them up and down the hill with me every time I headed out. Fingers crossed nobody nabs them! I've attached a note in waterproof ink, but realistically the chances of anyone finding them are pretty low and the risk of them being stolen if found are even lower. 

I'll do another of these round-up type blogs at the end of January. My mid-month tallies are 10 spiders (plus 2 harvestmen) and 7 flies. I'd like to see both of those tallies doubled by month end, maybe trebled in the case of the flies. But expect more posts between now and then! 

As for my challenger, he recorded his first hopper today. And so it begins.......

Inside a Catkin

Yesterday evening, whilst mooching about on FB, I was made aware of the existence of the Semudobia gall-midges which lay their eggs into developing female birch catkins. Looking on the NBN maps for each of the three species it appears that they are a widespread genus but massively under-recorded. None of the maps show records from the Skye area. Today, I duly headed into Uig Wood in search of last year's birch catkins. 

The only birch to occur in the Uig area is Downy Birch. It may come as a surprise to hear that Silver Birch is entirely absent from Skye, although one apparent hybrid Silver x Downy Birch tree was found in the south a couple of years back. I didn't know if Semudobia utilised Downy Birch or if it was restricted to the nationally commoner Silver Birch, but hey - if you don't look you'll never know, right?

Yet another gorgeous day - though rather chilly in the shade on this side of the glen

I had quite a good hunt around for Downy Birch in the woods and found maybe twenty trees. Despite spending quite a long time staring into their branches, I only found two individual catkins on one tree and none on any others! Well, that lowers my chances to a big fat zero, I thought to myself. Nevertheless, I popped my prize catkins into a pot, had a further wander around the hill and then headed straight back indoors. Oh yeah, because as of today Skye has been lumped in with the mainland and is now in Level 4 Lockdown, the highest level there is in Scotland. From Level 1 to 4 overnight, utterly ridiculous, but there you go. It is what it is, my small footprint in this world decreases in size once more. 

Spilling the catkins onto a bit of plastazote beneath my microscope, I began by loosening all the seeds from the stem in order to check them for signs of galling. I soon noticed that several scales would not easily rub loose, they were fixed to the stem itself. Ooh, that's a characteristic of one of the three gall midges I was after, could I actually have jammed in on some just like that??

After teasing out all the loose seeds and scales, these ones remained attached

The galls in the image above are the swellings on the stem with the wings of a seed directly above them. The two galls on the upper right hand side of the stem are probably the clearest ones to see. Ordinarily the seed would easily fall free from the stem, but the woody swellings have glued them tight.

I had to confirm to myself that this was indeed one of the galls I was after, even though it matched the illustrations in my gall book, so I very carefully peeled one open in search of the solitary grub within. 

Solitary orange grub - that's what I'm after! 

Two species of Semudobia gall the seed itself, distorting its shape and causing an under-development of the wings. The third species is the one above, Semudobia skuhravae. There are better images than mine on this site and on this site too. 

Whilst checking the catkin for more galls, I spotted a tiny black pupa hanging out from beneath a bit of scale. It's definitely not one of the gall-midges, in fact I think it looks more hymenopteran than dipteran, if so I guess it's an inquiline or parasitoid species. I'll try to rear it through, though my success rate is rather 50:50 with these things. 

Approximately 2mm in length

I found this paper online regards the various parasitoids of Semudobia larva and it even provides an identification key to the adult wasps that emerge! It's a European key, though written in English, but it may well cover all of the British occuring species too. I'm really hoping it is a wasp and that it does emerge, just so I can have an attempt at identifying it. Somehow, I rather doubt there are many folks in Scotland looking at these.

First Lifer of the Year

Another glorious day demanded my attention, so I took the sieve and tray up into Uig Wood in search of spiders in the leaflitter and tussocks. I had high hopes of a good few specimens running around in the bottom of the tray and I wondered how many species I'd identify from the hoped for haul. 

I'm ready! 

Just look at that lovely clean tray, it hasn't seen any action for months! That soon changed once I started adding handfuls of Rhytidiadelphus and leaf litter into the sieve and giving the whole lot a decent bout of shaking.

The arachnologists' moss of choice, or so I've heard

I took a quick pic of the year's first sievings for posterity. I shouldn't have bothered, there was bugger all in there!

Lifeless and barren

I had more luck shaking tussocks over the sieve (forgot to bring up a knife) than from sieving the leaf litter and mosses, resulting in a few fungus gnats from the family Mycetophilidae, plus a couple of tiny chironomids which I studiously ignored. There were a handful of linyphilid spiders, only one of which was an adult. It keyed through to one of about nine species and the palps matched Tenuiphantes zimmermanni perfectly. Damnit, I keep finding T.zimmermanni, a bit of variation would be nice.  

I also sieved a couple of sphaerocerid flies, the so-called Lesser Dungflies. Well, these were each around 2mm long, so I certainly won't argue with the 'lesser' part of their name! I tried keying one, but kept going wrong somewhere. I've put it into the Backlog Box for now, I shall try it again soon. The second fly I had more success with.

As I mentioned, at 2mm body length this was not a large fly!

There was one thing in particular about this fly which struck me as a little unusual. Can you see it?

The thing that struck me was the short wing length. Surely it couldn't actually fly with those tiny things?? I have a copy of the RES Key to Sphaeroceridae kindly passed to me by Murdo of the HBRG in the hope that I can put it to good use. Well I did today! Looking through the introductory chapters, I discovered that several species of sphaerocerid exhibit some degree of brachyptery so I was heartened to learn that I probably didn't just have a runt mutant on my hands. 

There are somewhat over a hundred species of Sphaeroceridae and, as always, where unfamiliar with a group it's a good idea to key the specimen to the correct family for starters. With flies this very often requires a check of the wing veins and their precise distribution across the membrane.

Reduced number of veins, no anal vein, the basal and discal cells are merged into one and vein M1+2 fails to reach the wing edge. That in itself is enough to place this fly in the family Limosininae, but we can add an extra confirmatory character simply by checking the hind tibia, which lacks a strong ventral seta. Squint your eyes and you should be able to see the lack of such a bristle in the following pic. 

I know it's rubbish - just remember the entire fly is only 2mm long!

So we're now in the key to Limosininae, which is by far the largest family in the British Sphaeroceridae with over 90 species. Gulp. A massively abbreviated version of the key to species now follows:

1 - Scutellum with discal setae in addition to the marginal bristles >>2

   - Scutellum lacking discal setae, it just has the marginal bristles >>10

The scutellum is the padded area at the rear of the thorax. I've marked it with a red dot in the image above, plus I've marked the bases of the four marginal seta in orange. You can see that the disc of the scutellum is bare, no hairs at all. 

10 - Scutellum with more than 2 pairs of marginal setae >>11

    - Scutellum with just the 2 pairs of marginal setae >>22 

Well we just covered that in the image above, there is a basal pair of setae and an apical pair, no others.

22 - Mid first tarsomere with long ventral seta >>23

     - Mid first tarsomere lacking a long ventral seta >>26

The couplet is asking us to look at the first segment of the tarsus on the middle leg. Nowadays this is usually called the basitarsus, tarsomere is the same thing though. I've spared you what would have undoubtedly have been a truly awful image, because I've just realised that I didn't take a photo of that feature (or lack of) at all! Don't worry though, the next image is a corker in terms of being completely shite. Anyway, there was no long seta on the ventral side of the first tarsomere.

26 - Mid tibia with a pre-apical ventral seta (there is more to this part of the couplet) >> P.fenestralis

    - Mid tibia without a pre-apical ventral seta >>27

Right, so here's your shocker of a pic. I've highlighted the relevant bristle for you. 

I mean c'mon...who else would go to this much trouble for you?

Well, that seems to drop us out at Pteremis fenestralis, better just check the rest of the first part of that couplet makes sense when applied to our fly. 

The entirety of it reads as follows: Mid tibia with a pre-apical ventral seta. Wings either reduced or not. Vein R4+5 curved forwards and distinctly overpassed by costa. Mid tibia with pair of dorsal setae in basal third. Plus some nonsense about the genitalia which I hadn't hooked out or placed beneath a microscope slide. 

Breaking it down, we know the pre-apical ventral seta is present on the mid tibia (the big red arrows are pointing at it!) We know the wings are reduced, I doubt it could even take off never mind actually fly. Vein R4+5 is curved forwards and the costa does extend beyond its tip. Pic below to show just that with vein R4+5 in red dots and the costa in golden dots.

This is Pteremis fenestralis, a new fly for me and only the second sphaerocerid I've managed to key through. The blurb reads that this is a common fly across Britain with females being commoner than males. Usually found amongst grass tufts and in mouse runs (no disputing that!) and that all populations in northern Britain comprise the brachypterous form. Sweet, I was chuffed with that. 

What I wasn't quite so chuffed about was the comment that Ali left after seeing this unaltered image

"...I was gonna say Tomocerus because I can never remember the new name. Is that Pteremis fenestralis, perhaps?" Bugger me, but he's good is that chap!

I found a nice article that goes on to describe the varying degrees of brachyptery in some detail. Here's a pic which shows how wing venation slowly reduces with decreasing wing size, all very interesting stuff. 

Winter Plans

I've tended to move around the country a bit over the years. I started life in the Midlands, then headed down to London, back to the Midlands, up to Scotland, down to Surrey (and that was all before I'd even left school!) and a few extra places in between since then. And now I'm on Skye, the furthest north I've ever lived and I'm loving it. 

However, the flipside to being this far north is that there's not a huge amount of daylight during the midwinter months and it's usually pretty wet when it isn't being dark. Yesterday's beautiful weather was a stunning exception, and actually today wasn't too bad either once the rain passed. But I do need to come up with some sort of a strategy that will keep my Challenge from stagnating at this quiet time of the year. Hah, Day 2 and already I'm worried!

It turns out that the Skye winter weather can be a bit shitty at times, who knew! But being this close to the sea means we don't really experience much in the way of minus degree air temperatures here in Uig. Of course, the wind can happily make up for that. But the winter-active spider and fly species are all used to that, they will still be around whether it's a crisp clear day or a horrible icy wet night. They don't just disappear, they still have their lives to lead. The point I'm trying to make is that spiders and flies are always available to find, it's just a lot easier to find them when the weather is calm and mild rather than in horizontal sleet and snow showers. 

Alright, so we know there's stuff to be found here in midwinter. How best do I find it? There are options. 

Firstly I could be very lazy and still manage to find a few flies and spiders. How? Just stay here in the hotel and see what turns up. Spot-lighting the white walls after dark is one easy method to find flies and spiders, none of which happen to be white bodied, so that helps. In fact, lazy or not, I plan to do precisely that on a regular basis. It's just a great way to find additional species, and some of the flies at least won't be around in the summer months. My second lazy trick concerns the outbuilding in the gardens. It has an internal light that never turns off, not unless I kill power to the whole building at least. It has large double doors which are always wide open, thus it attracts quite a few flying insects at night. Which in turn attracts spiders. A couple of years back, I painted the walls and ceiling a horrible insipid pale magnolia kind of colour. It really is quite a revolting colour, but it does mean that any insects and spiders sitting on the walls or ceiling now show up rather well against the pale background. All clever stuff, huh? This outbuilding houses the washing machines/tumble dryers, so I do have a legitimate excuse to loiter in there from time to time anyway. 

Or I could be a bit more pro-active in my endeavours to find species. Let's look at the spiders first. 

Lots of spider folk go out with a sieve and white tray, grab handfuls of moss and give it all a good shake. The moss stays in the sieve and the spiders fall through and into the tray. Something like a cheap cat litter tray is ideal, though naturally I went ahead and bought the entomological version which is maybe two inches deeper, won't fit into my rucksack and cost around nine times the price of anything I could have picked up in a pet shop.

I've seen this moss-sieving technique used before on the dry, chalky South Downs. But I'm on peaty gleys where everything is wet, especially at this time of year. I'm still going to give it a go regardless, worse case scenario is that I get wet hands and no spiders. Winter is the season that many money spiders become sexually mature, and hence identifiable, and the north west of Britain is actually very rich in money spider diversity. Uig Wood is the largest patch of broadleaf woodland in northern Skye, I'm thinking there must be some really good species in there. That logic applies equally well to the flies too, I imagine. Though not in January, their time is still a few months away yet.   

My nocturnal hunts needn't be confined to the walls of the hotel either, I suspect tree trunks and fence railings will provide me with excellent opportunities to find spiders on the prowl after dark. Uig Wood is a mass of tree trunks. My beating tray is about 3ft square and has flexible edges, I could probably push it tight against a tree trunk and brush the mosses, lichens and bark above with a paintbrush. That should provide me with quite a few specimens, I reckon. 

Regards finding more flies, I think I may have to set out a few bait traps and start rootling through the rotting piles of grass clippings and leaves that I created whilst mowing the lawns. I need to be aware of disturbing hibernating hedgehogs, but they should be at quite a depth I'd suspect. Certainly deeper down than the flies I'm after. 

There are also the larval stages to consider, as the Dasysyrphus albostriatus from yesterday proves. Most of the mature trees in Uig Wood are either Wych Elm or Sycamore. Both have a rich aphid fauna, which means there are plenty of aphidophagous hoverfly larva just waiting to be found in the leaf litter. I did a bit of leaf litter larval searching last year and found a few species. It was quite good fun actually, though most larvae remained unidentified. It's something I shall definitely be doing again soon. Finally, there are leafmines to look out for. The agromyzids have leaf and stem mining larvae, a couple of which are relatively easy to find here on Skye, even in the winter time.

I plan to populate this blog with images of my finds, the habitats I explore, even of the kit I'm using. But I didn't take any photos today and I'm determined not to use old images from last year. So here's a photo of yesterday's male Metellina merianae showing you his boxing gloves. The pedipalps of male spiders are sometimes quite extraordinarily over-developed with prongs, teeth, balloons and spurs sticking out at the most unlikely of angles. This one appears to be wearing mittens with immense hooked thumbs! 

 

First Hoverfly of 2021

Today turned out to be a beautiful day, hardly a cloud in the clear blue sky, snow on the hilltops, a crisp northerly breeze in my face but the air not so cold that I needed gloves. Pretty darn wet underfoot, it has to be said. We've seen a heck of a lot of rain recently! 

I took myself into Uig Wood and checked tree trunks for roosting craneflies (couldn't find any), thought about sweeping the low vegetation (too wet) or tussocking (again, too wet) so ended up grubbing through mosses and lichens on tree trunks and shaking aeriel debris into my sweep net. Not a particularly productive way of finding spiders and flies, but I found a few. 

2mm of male chironomid midge. Way beyond my skills, I let him go

Adult male Metellina merianae - spider No.5 for the Challenge

The woods really were very hard going, and after an hour or so I decided to quit and head across the sheep fields towards the cemetery where I could check in a drystone wall for signs of life. I picked a random bit of fence line to cross, put my hand on a post for balance...then stopped as I saw this

What on earth is that?

A closer look was obviously required

It's a hoverfly larva! 

If you look really closely, you can see a pair of breathing tubes sticking out at the top end (actually the rear, the larva is positioned facing head downwards). I figured it was a Dasysyrphus, but there are several species that occur on Skye and I didn't know if this could be identified to species as a larva. However, I know a man who does! So I popped the pic on the UK Hoverflies Larval Group's FB page and within a few minutes was informed that it was a Dasysyrphus albostriatus and the first larval hoverfly record of the year on Facebook! Yay....so what do I win?

Continuing to the cemetery wall, I began by surreptitiously checking no crofters were watching, before carefully lifting the top stones in search of spiders. I know all of the local crofters now, a bit of a rough and ready bunch to be fair, but they're usually pretty decent types. However, nobody likes it when 'idiots' begin pulling apart the walls. I'm certain I could talk my way out of any trouble, but it's probably best not to deliberately wind them up wherever possible. As it happens, I found more in ten metres of wall than I did on the trees!

A young Megabunus diadema - it must have been all of about 2mm long!

This is a female Trichocera saltator (keyed indoors) seemingly trying to push a rock up a hill...

And this is a liny (money spider) which is currently causing me some problems

There are only two ways to go about this Challenge when it comes to the spiders. The first option is to buckle up and crack on with all of them, no matter how big or small, just get on with it and see how you progress. The second option is to say "Oh shite, that's a money spider. Bollocks am I doing that" and just stick to the big easy stuff. Hopefully you all know I'm never going to take that second option. That's akin to running a moth trap and ignoring all the micro's 'coz they're too difficult' and obviously nobody does that... 

The way I see it is simple. There are shedloads of linyphiid spiders out there (linys for short, the money spiders basically). It will be impossible to avoid them whilst looking for other spiders, and indeed whilst sweeping for flies too. I've spent lots of money on decent literature specifically to put myself in a position to tackle them. Provided they are sexually mature - which means they are fully developed and hence identifiable - I will collect them in an effort to become more proficient in their identification. But some of them are pretty hard to ID. And this one's identity is currently proving a tad tricky to nail. 

Quite a distinctive epigyne, you'd think it would be easy to find a match

I ran it through the keys, taking count of the number of leg bristles on certain tibia and metatarsi, noted the absence of a trichobothria on one part of one leg, checked it's position on one part of another leg, came up with a formula, measured the whole spider at 3.5mm, ran it through the keys and came out with, I think, eleven possibilities. Picture matching the epigynes narrowed it to the genus Centromerita, with a couple in the genus Centromerus as outside possibilities. But nothing conclusively matched, no matter which images I looked at in my books or on various websites. 

Eventually I caved and put the images up on the UK Spiders FB Group with a plea for help. So far I've had one of the Centromerus species suggested, so at least I'm in the right area, but nothing conclusive. I'll try again tomorrow, with fresh eyes. 

My 2021 Challenge tally so far stands at four flies, seven spiders and one harvestman. A steady start, I think. I need to try and keep from developing any backlog specimens for as long as possible, before it all kicks off in the spring. Baby steps, I've a very long way to go yet!