Saturday, June 22, 2019

Passengers

On a 'photo safari' at Bowlees quarry in Teesdale, a group of invertebrate enthusiasts were rewarded with some great species sightings, and a couple of things in particular gave me the theme for this post.

A decomposing rabbit carcass was providing a banquet for flies and carrion beetles, including the large and conspicuous Red-breasted Carrion Beetle (Oiceoptoma thoracicum), which I always think is mis-named; surely Red-shouldered would be more apt...




These are part of a community of creatures that do the dirty work of disposing of corpses, and whilst it may be a bit whiffy getting up close to photograph them in this environment, they're great beetles to watch.
On to the real theme of this post though, and several of the carrion beetles were carrying a cargo of mites, which were very active, running around on the beetles and onto the carcass. Here they are on another species which was present in numbers - Thanatophilus rugosus -



These phoretic mites belong to the same class of animals as ticks, spiders and harvestmen - Arachnida, and hitch a ride on the carrion beetles as a means of transport for getting from one food source to another.

Other invertebrates found at the quarry were also acting as a transport system. this time for a plant. We observed individual soldier beetles, false blister beetles and craneflies with strange yellow protuberances on their heads. Here's a cranefly -


Never having seen this before, there was speculation as to what it might be, and why different species were displaying it. Could it be a fungal growth? The answer is that these are orchid pollen sacks. Unlike flowers which rely on individual pollen grains adhering to insects, orchid pollen is contained in these large pollinaria, which are equipped with a sticky pad that attaches to the insect as it enters the flower. The pollinaria are then transported to another orchid by the carrier. So it's pollination, but not by a means that I've ever seen before. I suspect that someone with expertise in orchids may be able to identify which species it originates from by examining the size and structure. Very interesting stuff. There's always something new to learn.

You can find details of upcoming events by the North Pennines AONB's Cold-blooded and Spineless project at-
http://www.northpennines.org.uk/events-calendar/






Sunday, May 26, 2019

Wait a minute. That's no ant!

A sunny day in Rookhope Valley, and while stopped for a rest I noticed that an ant was scurrying around on a nearby rock. Initially I thought nothing of it, but then I began to wonder where all of its pals were. Ants are social insects and surely after a couple of minutes this one shouldn't still be running around on its own? Taking a proper look at it, I realised that it wasn't an ant, but an ant-mimicking spider of the genus Micaria.

Micaria pulicaria



And a very convincing ant-mimic it is too, not so much in the appearance in photos, where it just looks spidery, but in the way it moves. It certainly fooled me, and the theory is that this is also to fool potential predators.
If the photos aren't particularly good, it's because this species also represents a quite a challenge to the photographer. This species is only about 3-4 mm in size, and never stays still! I spent a good 20 minutes chasing this individual around a lichen covered rock where it was presumably looking for prey, and these are the only 2 usable photos out of dozens that I took.



Micaria pulicaria


I've captioned the photos as Micaria pulicaria, but there are actually 5 very similar species in the UK and they can only be reliably identified by microscopic examination of a specimen. This is the only one that's anywhere near common however, especially in this part of the country, and the other 4 species are classed as nationally rare or scarce. And anyway, it's my blog, so I'm calling it Micaria pulicaria, so there. Probably.

Thursday, May 16, 2019

Deadly Embrace

That was dramatic eh? Deadly Embrace? It was just to hook you in to look at some pictures of flies eating other flies. And embracing them while they do. Well, sort of.
A rare spot of fine weather saw huge numbers of  St Mark's Flies (Bibionidae) swarming the riverside area of the River Wear near Stanhope. And some of them were falling prey to predatory flies in the family Empididae (Dagger Flies, or of you prefer, Dance Flies)



If you're wondering why I'm being a bit shy about putting names to the species shown here, it's because these families of Diptera are somewhat outside of my comfort zone, and I don't have any definite identifications as yet. If I get any definite IDs, I'll add an update. So for now, it's just "Empididae having Biobionidae for lunch."

Tuesday, May 7, 2019

Opilione Opportunity

I'll be back-tracking a bit with some blog entries, since I've fallen more than two years behind, so I apologise to my imaginary readers if we go back and forth in time and the blog isn't a strictly linear diary of the changing invertebrate seasons.

Back to 20th April. Remember those few warm days which now feel like maybe that was the Summer? Well, on that day I had to go no further than my own garden to find a splendid new (to me)  species of Harvestman - Platybunus pinetorum. This was first recorded in the UK in 2010, and there are still very few confirmed records (this may be the first for the North-East), but it seems to have spread across the country at an impressive rate, and I suspect there are many more than we realise.

Platybunus pinetorum, female.




Opiliones are a group that don't seem to attract a great deal of interest, and therefore suffer from under-recording. I'm really starting to warm to these charismatic arachnids though. There's an excellent interactive online resource from the Field Studies Council -

https://harvestmen.fscbiodiversity.uk/

I think you need to take a close look at them (and this is where photography comes in) to realise that they're more than just a featureless grey blob with some ridiculously spindly legs attached. Unlike spiders, they have two dark eyes set in a little turret (the ocularium), which I think gives them a strangely mammalian appearance.

Platybunus pinetorum, female.
This Platybunus is among the more strikingly marked species, and also bears an impressive row of fearsome looking spines on the pedipalps. It's a species which is active in Spring, so now's the time to take a closer look at any Harvestmen you see, and see if we can get a few more of these on the map.

Platybunus pinetorum, female.
A more familiar little arachnid got a look in the same day too. This time a Salticus scenicus, one of the jumping spiders (Salticidae), and probably the one spider that is least likely to upset arachnophobes. They're very small, and cute.

Salticus sceneicus.
Salticus sceneicus.

Sunday, April 28, 2019

Rainy Day Diehards

An afternoon session of  invertebrate hunting as part of the City Nature Challenge 2019 saw temperatures tumble and was accompanied by near constant drizzle.
A small (very, very small) but determined band of enthusiasts had to work hard for a very few sightings. In gaps between showers I managed to get the camera out and capture one or two creatures hiding under the bark of fallen timber, like this rather soggy but still magnificent Banded Centipede - Lithobius variegatus

Lithobius variegatus.

I'm guilty of not paying enough attention to centipedes, or to any of the Myriapods, or Isopods, for that matter. They're a tricky group for a lazy chap like me to get to grips with, but this is one of the few species that can be easily identified from a photograph, as the strongly banded posterior legs and markings on the body are distinctive. The yellow-ish, banana shaped bits that run down either side of the head? They're the poison claws, which from the underside (sorry, no pictures...) can be seen to terminate in the sharp venomous claws with which the centipede kills or paralyzes its prey.

Another find among the rotten timber was one of the Amaurobiidae, or Laceweb Spiders. This is not one where I can be certain of species, unfortunately. The location and habitat might make me lean towards Amaurobius fenestralis, but it can only be reliably distinguished from Amaurobius similis (the name says it all), by close examination of its cheeky bits. So we'll have to leave it at Amaurobius sp. for now.


Amaurobius sp.



Sunday, April 2, 2017

Hibernation (mine) is over...

   It's been a while, and a long winter, since my last post. Signs of Spring have had me itching to get out and find some invertebrates but opportunities have been limited. Yesterday I spent a couple of hours at Marley Hill and on the Bowes Railway path, looking specifically for Gorse Shieldbugs (Piezodorus lituratus). They're a species which can be active early in the season so I thought if I could locate 1 or 2 they'd be handy subjects for getting my eye in with the camera work. There were dozens of them in evidence, though most were hiding down among the gorse leaves. I did find some posers though.

Piezodorus lituratus

Friday, October 21, 2016

Scary (not really) Sawflies

  Sawflies seem to be the neglected relatives of the order Hymenoptera (the bees, wasps, ants and sawflies). They belong to the suborder Symphyta, and are represented earlier in the fossil record than their more glamorous, upstart cousins. Fossils of the Xyelidae, a family of sawflies with some species still buzzing around today, have been found in rocks dating from the Triassic - between 245 and 208 million years ago.
  There are around 500 species of sawflies in the UK, and they're mostly quiet, unassuming insects and often difficult to identify to species level, which may be why they aren't more 'popular'.
   However, in August this year I photographed one of the more spectacular species, Urocerus gigas. This female was flying around the top of High Force in Teesdale, and is such a large creature on the wing that I at first thought I was looking at a dragonfly. It wasn't until she obligingly landed near me that I realised what she was. My intrepid partner, not entirely convinced that the 'sting' wasn't a sting,  was brave enough to point a finger at the beast, to give a sense of scale for the photo.

Urocerus gigas

  Commonly known as the Giant Woodwasp or Greater Horntail, this female was over an inch long and a very formidable looking insect. There's no need to be scared of the 'sting' in the tail though, as  it's only used for drilling holes into felled or diseased trees to lay eggs. The larvae develop by feeding on the timber, burrowing tunnels as they go. Because wood is such a poor source of nutrition, it may take the larvae several years to develop to adulthood.

  In September, on the Banks of the South Tyne, Near Garrigill, we found two individuals of a related, if not quite so colourful species - Sirex juvencus, laying eggs into a tree. Known elsewhere as the steely-blue woodwasp for its colour, it's a species which seems to have very few records in the North-East. Like Urocerus gigas, it's considered a pest by the timber industry.

Sirex juvencus