Woodlice Parade

Woodlice are the easiest crustacean group to spot in the garden. Sure, your garden pond will likely contain several aquatic crustacean groups: Water Fleas, Copepods and Ostracods are likely. Woodlice are amongst the few crustacean groups that are truly terrestrial - although aquatic forms both freshwater and marine are also found.
Despite their terrestrial habits, woodlice species differ in how much humidity they need to survive. Some can live in very dry habitats, while others need a constantly high level of dampness.
 There are over 45 British species of woodlice, of them I have found six locally. Here I have put together a parade which might help you identify your garden woodlice.


1. Common Pill Woodlouse, Armadillidium vulgare. Pill woodlouse are quite resistant to low humidity conditions and live in dry, sandy habitats. When disturbed they roll into a ball, protecting their legs and antennae.

2. Rough Woodlouse, Porcellio scaber. Another species that can live in relatively dry habitats, like under pots. Recognised by its matt, bumpy grey surface. They tend to grip the ground with their legs when disturbed, making it difficult to dislodge them as their flared segments form a continuous surface with the ground, and then they can walk more or less fast. Very common and often found in large aggregations in suitable habitats (top shot).

3. Smooth Woodlouse, Oniscus asellus. A large, flattened woodlice with a shiny surface. As the rough woodlice, it tends to freeze and sit tight, making it hard for predators to dislodge it from the ground, although it can also move away. It is one of the largest woodlouse species in the UK.

4. Common Striped Woodlouse, Philoscia muscorum. Amongst leaf litter. A fast woodlouse, which rapidly hides when disturbed. Beautifully patterned, shiny with a dark head.

5. Rosy Woodlouse, Androniscus dentiger. A small species which favours damp habitats with rotting wood or organic material. Pinkish with a yellow dorsal stripe and dark contrasting eyes. It is the rarest in my garden.

6. Water Slater, Asellus aquaticus. Found in the leaf litter at the bottom of ponds. Long antennae, although many lost due to fights, then they regenerate (see photo below). Males larger than females.

More information
A key to British woodlice by Jon Rosewell, in the iSpot resources.
Walking with Woodlice, a Natural History Museum project.
Browse BugBlog's woodlouse related posts.

My spider year

I set up to take Alex Wild's (Myrmecos) challenge to select my best 2012 photos. I started going through the 7,405 photos I have kept this year and was quite daunted by the task as I find it difficult to compare across topics, animal groups, macro/not, etc. Then, after checking quite a few I thought that 2012 has been a great spider year. I have learned so much about their natural history and behaviour, and welcomed quite a few new species in the garden so I thought I'd made a selection of the best. It was fun to take part in the challenge, and I hope you like them.

This is a wolf spider of the genus Pardosa. This year I was privileged to witness its amazing courtship.

Males tiptoe as they slowly approach a female, while signalling with their pedipalps.

A few weeks later, the female's abdomen is distended with developing eggs

And then she lays her eggs and wraps them in a silky sac that she carries about secured to her abdomen.

The best feature to the Holiday Inn in Standsted Airport was this Spitting Spider, Scytodes thoracica. This species spits out a criss-cross of sticky silk that paralises its victims

In our holiday trip to Asturias we saw this Spider Wasp (Pompiliidae) carrying a paralised crab spider, probably Xysticus sp across the road. 

 A bunch of Enophlognata ovata females were inadvertently taken to the recycling bin after some shrub pruning. I moved this one to the white bowl and she dragged her blue egg sac with her on a strand of silk.

Steatoda bipunctata, the common false widow spider is an abundant species in the garden. This is a female.

And this is a male. Males in search of females often run on the ground and look remarkably like common garden ants, Lasius niger.

Despite its small size, this spider can subdue ferocious digger wasps. Queen and male ants trying to disperse often fall prey to it.

This is my favourite spider photo of the year. It shows a female Pholcus phalangioides with her newly hatched spiderlings. She holds her eggs, loosely wrapped in silk, in her jaws until they hatch. The newly hatched spiderlings remain with mum for a day or so...

And then they settle not too far away. Here you can see the empty egg shells still held by the female. The spiderlings stay with mum for a couple of molts and then disperse. Presumably they do not feed during this time.

Araneus diadematus is one of the commonest UK spiders. This is a male.

Here a male in the foreground explores the edges of a female's web (upper felt side corner). He might spend several hours approaching the female, sending vibrations down her web. Any wrong step and he might fall prey to the female's appetite.

The feared bath spider, is often a male Tegenaria sp., which, in his wanders in search of females, falls trap to the slippery slopes of the bath.

I learned quite a bit about this spider, Amaurobius similis. Here a male, by a windowsill, wanders near a female's retreat.

A few days before I had watched her 'carding' her bluish silk at night.

Amaurobius is a fierce looking species. A female jumped out of her retreat at tugged at a ladybird's leg. A few seconds later, she let her go, maybe finding it distasteful.

In March, this Amaurobius female was tempted our of her retreat by a bee that got tangled on a thread of her silk - and that I was trying to photograph - the bee escaped unharmed, but it allowed me a photo of this female spider in the light of day, and showed nicely her bluish carded silk threads.

This is a horrible photo, I hope I have the chance of finding this again next year. Upon lifting a pot I found this Dysdera crocata holding its dead woodlouse prey. Unfortunately when I got the camera the spider had already retreated and this is the only shot I got before she run away.

In 2012 a new spider species, Pisaura mirabilis, the fascinating nursery web spider, appeared in the garden. One specimen, a young male (top shot) stayed for days on our garden back fence and let me take his portrait.

Philodromus sp., a relative of the crab spiders, are tiny spiders which like to bask on or near flowers. This one has captured an aphid.

I like this photo of a Zebra spider, Salticus scenicus, as it appears to be looking intently where to jump next. 

This is a mature female Mouse Spider - I think Panther Spider would be a better fitting name for this beautiful spider. I love her dark, glossy coat and powerful look.

A natural white background exposes this Araniella sp. These tiny orb weavers are normally quite camouflaged in the shrubs and bushes where they live.

Another new species for me this year, an iridescent male of Philodromus sp.

Although the tropics are much richer in ant mimic spiders, some species can be found in the UK. This is Micaria pulicaria. It likes to run on the ground in the company of garden ants, Lasius niger. It carries its forelegs pointing forward in a way reminiscent of the ant's antenae.

We found this field covered on gossamer, fine silk threads used by money spiders to balloon. Click to embiggen and see the tiny spiders in the middle of the photo.

Overwintering

 BugBlog has been dormant for a few weeks. Somehow, posts somehow never went past the project status. But today, the sun shone after days of rain and gloominess, and in a walk at the park, my 4 year old and I did an informal ladybird survey. We checked many tree trunks and spotted lots of ladybirds, not as many Harlequins as other years, but still the easiest ladybird to find in the park. They were quite active as it was mild, and walked on the tree trunks in the sun. More than 40 in total, as the cluster of Harlequins above nestled in a little hole on a tree trunk was a little tricky to count. A single 2 spot ladybird completed the survey.

Dapper spider

Unfailingly, house spiders, Tegenaria sp. males go on a walkabout this time of year looking for females. This male sat on our outside wall for a couple of days, all exposed. Love is a dangerous affair for spiders. After their last moult, when they reach maturity, they move often in the open, away from its silky shelter, where predation is more likely. This same week, flocks of Long Tailed Tits, and Coal Tits have roamed the garden, the latter paying special attention to walls, poking into holes while deftly holding onto the wall.

Loving the ivy

The late flowers of the ivy are a bug magnet in the autumn, when other sources of nectar are scarce. I have posted before on ivy fest season, but today I came across some new ivy visitors in a large ivy just starting to bloom in my local cemetery. Speckled Wood butterflies rarely visit flowers, as they usually feed on honeydew produced by aphids up in trees. So, I was pleasantly surprised to see two individuals feeding on ivy together with a Comma and many Droneflies.

Speckled Wood and Comma

Comma

Dronefly Eristalis tenax

Male wasp

Helophilus

Yellow dung fly?

Drinking spider

The sky was clear of clouds and the temperatures have come down in the night. A dew covers everything in the garden, including a female garden spider, Araneus diadematus, with a large, distended abdomen, nearly ready to lay eggs. She is hiding under her dry leaf retreat on the honeysuckle, and using her rear legs to collect the dropplets of dew on her abdomen. She repeatedly makes a brushing motion and then licks the tip of her leg.

Daddy superlong legs

Today's post celebrates harvestman season. This one, a male Leiobunum rotundum, sat on an outside wall, all outstretched legs. With an enormous leg span, well over 10 cm, it is amongst the longest legged harvestman in the UK. The species can be recognised by its dark mask around the eyes and contrasting black legs. Males have a rounded orange body, while females are brown-grey with a broad dark stripe along her back. The next photo gives you a idea of the relative size of the legs in proportion to the body.

Garden Snail Parade

Since I started this blog, I have been surprised by the diversity of land snails about in the city. As I have managed to get most of them on white background, I decided to write a post and display them all together.

Moss snail, Lauria cylindracea, a tiny, easily overlooked species which gives birth to live offspring. 

Garden Snails, Helix aspersa (=Cantareus aspersus), unashamedly mate in the middle of your garden  path throwing darts at each other. 

Girdled Snails, Hygromia cinctella, like walls. An introduced species since 1950, still expanding across Europe from the Mediterranean.

Kentish snail, Monacha cantiana prefers drier places. This species, introduced in the UK during Roman times, is a very common snail in my local Wildlife Garden. They can be darker with pale speckling.

Glass Snails, Oxychilus draparnaudi, are carnivorous snails that have caused havoc on native snails when introduced outside the UK.

Amber Snails, Succinea putris usually live in very damp places, but can be also found away from water. They cannot completely retract their bodies inside their shells.

Brown Lipped Snails, Cepaea nemoralis are very polymorphic in colour and pattern.You might be lucky to have these beauties in the garden.  

Have you noticed all the snails are facing to the right? This is because most (90%) of all snail species have right-handed shells (dextral). Occasionally a left-handed individuals appear in populations of right handed snails. These face a problem when trying to mate, as the genital opening will face away from most other snails in the population. The genetics of shell handedness has been elucidated in some species and appears to be determined by mutations in a single gene, but the left-handedness trait is expressed not in the mutant, but in the resulting offspring.

More information

Visit the Molluscs posts in Bugblog.

Terrestrial Mollusc Tool. A wonderful resource for US molluscs. Contains also lots of info on introduced European slugs and snails.