Articles in ‘Spiders’

A diversity of spiders

Written by Lucy Brzoska

If you wish to live and thrive, let the spider run alive 

Enthroned in a Pitch Trefoil flower, the Heather crab spider (Thomisus onustus) had arrayed its legs like a multi-limbed deity.  The colour of raspberry-ripple ice cream, it blended in well with the purple bloom where it meditated, invisible to prey and predator.  Enormous forelegs lay in wait.

It’s always worth getting up close and making eye contact with a Jumping spider. This female Carrhotus xanthogramma was spotted on a Common Smilax leaf.  

Her abdomen has handsome tawny markings.

Shining a torch in a spooky underground chamber in the middle of Collserola’s woods revealed a colony of Meta bourneti – a Cave Spider of the Tetragnathidae family.   The light cast great leggy shadows on the vaulted walls and picked out the prominent black bristles.  Like other Orb spiders, these cave-dwellers rely mainly on these touch sensors to hunt.  They seemed to hang in mid-air, perfectly in tune with the vibrations in their nearly invisible webs.

The Wasp Spider (Argiope bruennichi) adds drama wherever it sets up camp.  There were several alongside Vallvidrera reservoir at the end of summer.  They’d slung their webs low down in the grass where dragonflies cruise.


 

In the jungle – Mediterranean insects

Written by Lucy Brzoska

It’s the month of May and plants are fighting for space. In the dense, overgrown jungle roams a large yellow beast (well, 2-3 cm long). It has the silhouette of an anteater, except for those antennae sprouting out of the snout.  The Yellow Weevil eats plant matter with mouthparts at the end of its “nose”.  The length of the snout allows it to bore where other insects can’t reach.

yellow-weevil-in-thistle-lixus-pulverulentus

Two Longhorned beetles mate, antennae mingling.  They look a bit like chamois, except their “horns” are flexible and longer than their own bodies.

longhorn-beetles-mating-agapantia-cardui-suturalis

Flowers are for eating – this pollen-consuming jewel beetle (Anthaxia hungarica) is attracted to Compositae . . . .

anthaxia-hungarica-jewel-beetle

. . . . or for lurking in.  A napoleon crab spider, sprinkled with pollen, waits to ambush its prey.  It’s common to see the lifeless form of  a bee hanging from a flower, as the spider sucks it dry.  Sometimes the venom takes a while to work, and the spider clings on, going for a flight with its victim, not knowing where it will land.

napolon-crab-spider-synaema-globosum-covered-in-pollen

The vibrancy of this Spotted Fritillary (Melitaea didyma) reminded me of a tiger. On this windless cloudy day, the butterfly remained motionless.

spotted-fritillary-melitaea-didyma

Zooming in on Montjuic Castle (i)

Written by Lucy Brzoska

You barely notice the ants unless they’re lugging some eye-catching, outsize object, such as the remains of a woodlouse.  It was an awkward task, requiring tenacity and strong pincers.

ants-carry-woodlouse

Team effort successfully manoeuvred the crustacean through the crack.  There was barely any flesh on it but woodlice themselves will eat their own or each other’s cast-off cuticles.  The hard, over-lapping armour plating is made of calcium carbonate, a form of calcium we get in dietary supplements.  In any case, ants bring back all kinds of booty to  their galleries, edible or not.

ants-squeeze-woodlouse-through-hole

A jumping spider was darting among the busy ants:  Menemerus semilimbatus, a Mediterranean species often found on sunny walls and rocks.  Upside-down, it surveyed me with a fine set of four bright eyes.

jumping-spider-menemerus-semilimbatus

The other four are located on the carapace, slightly disconcerting until you get used to it.  Two of them are clearly visible here.

menemerus-semilimbatus-jumping-spider-from-above

Salticids are renowned for their visual acuity.  They hunt by stealth and pounce with deadly accuracy.  In their courtship dancing, the males often flaunt brightly coloured parts of their body.  Some species have impressive John Travolta disco moves (click on second image down).

Another movement caught my eye and I was just in time to see a soft downy feather disappear through a hole, as an ant whisked it into the depths of the castle wall.  You can only wonder what use the ants would find for it.

ant-carries-feather

Wolf spider in Collserola – Hogna radiata

Written by Lucy Brzoska

Something scurried across the ground in fits and starts: a spider with a bristling brown back.  I approached and found the bristles were a cargo of spiderlings.  Their mother, a Wolf Spider, was moving her brood in broad daylight along a track in Collserola.

wolf-spider-hogna-radiata-and-spiderlings

At first I thought it was a Mediterranean Tarantula (Lycosa tarantula), but the radial pattern on the thorax should have led me to Hogna radiata.  Another difference between the two species is that H. radiata doesn’t build a burrow, instead roaming to hunt its prey and using stones for shelter.

Looking at the tightly-packed brood, it was possible to make out rounded bodies and a tangle of spiky legs.

wolf-spider-hogna-radiata-spiderlings

Wolf spiders are dutiful mothers who carry the egg sac attached to their spinnerets, quite a burden for an active hunter.  The abdomen has to be kept raised so the egg sac doesn’t drag on the ground.  The mother spider will sit in the sun to warm the eggs, and when the time is right, chew open the silk case to free her brood.  She’ll wait until all the spiderlings have climbed on board and are clinging to her bristles.

Maternal care doesn’t go as far as feeding the young (as in other species, like the Mothercare spider).  Wolf spiderlings survive on nutrients stored in their abdomens and usually after a week they moult and scatter.

Wolf spiders are among the largest spiders in Europe.  H. radiata is only slightly smaller than the Mediterranean Tarantula, the female measuring up to 2.5 cm long.  Out in the open, the spider struck me as vulnerable and defenceless.  But the view from the front was quite different.

wolf-spider-hogna-radiata-with-young

The prominent dark eyes – which gleam in the dark if you go searching for it by torch-light – and strong hairy legs – the sprinting spider pounces on its prey like a wolf – warned me I was facing a formidable hunter.

Wolf spiders have far better eyesight than other spiders, and the eyes are arranged in a distinct pattern: a row of four at the bottom, two on top, and two enormous ones in the middle, all visible from the front.  Look at this fantastic close-up.