War of the Worlds

Harvestmen are animals that could have stepped straight out of a science fiction story. That globular body, slung between unfeasibly long angular legs, could easily be a Martian fighting machine, striding through hordes of fleeing, terrorised refugees in War of the Worlds....... or maybe I’ve got an overactive imagination..... but check out the CD cover for Jeff Wayne’s musical version of War of the Worlds (see http://www.coverbrowser.com/image/bestselling-music-2007/3826-1.jpg) and I think you’ll see what I mean.

You do need a pretty vivid imagination to come close to understanding how these strange animals perceive their surroundings. Those two eyes, on either side of the turret on top of their body, are not particularly effective and they mostly explore their surroundings using their senses of taste and smell, which are located on their palps, on either side of their mouth (just visible behind the front leg in the picture above - double-click on the image for a larger view)), and on their second pair of legs. Notice how, in the pictures above and below, this harvestman is lifting and extending one of its second pair of legs towards the camera – it’s smelling me. They take great care of that vital second pair of legs and if you watch one of these animals for long enough you’ll notice that it will draw each of this pair of legs through its jaws quite frequently, to keep these sensory limbs clean and in tip-top condition.

There are scores of these intriguing animals in our garden at the moment, striding through the dry grass and dead leaves in that cautious, fastidious way in which they move, searching for small insects to feed on amongst the decaying vegetation of autumn.

 

Deadlock

A while back I described an encounter between a wasp and a large yellow underwing moth (see http://cabinetofcuriosities-greenfingers.blogspot.com/2009/07/unlucky-moth.html) where there was only ever going to be one outcome, but today I watched a wasp grapple with a more formidable opponent where the winner was always in doubt. The wasp blundered into a spider’s web spun in an umbel of hogweed and after a frantic struggle managed to free itself, but not before the spider had leapt onto the wasp. They hung together in the wrecked web for a few seconds, while I took these pictures.

Each grasped the other by its opponent’s jaws, while the wasp couldn’t quite bend its abdomen down far enough to sting the spider. Deadlock. Then the wasp broke free and flew off with the spider still attached, so I’ll never know the outcome of the contest. Maybe, during its initial lunge, the spider managed to inject enough venom to kill the wasp and they both plunged to the ground, where the spider finished the job. Maybe the wasp stung the spider and settled to dismember its attacker. Which would you put money on? Anyone know what spider this is?

Naked Ladies

Yes, that is a cheap, attention-seeking headline; botanically, 'naked ladies' is nothing more than a slightly salacious name for autumn crocus aka meadow saffron aka Colchicum autumnale. This plant's ‘nakedness’ stems from its lack of leaves, which aren’t produced until spring – the beautiful lilac flowers, very attractive to bees, appear without any accompanying foliage in grassy places in early autumn. This is a rare wild plant and most specimens that turn up – like these beside a road in Weardale – are probably garden escapes. In the wild the plant was ruthlessly eliminated because it’s extremely poisonous to grazing livestock, thanks to the presence of toxic colchicine in all parts of the plant. Like many plant poisons colchicine has been used medicinally, in very low doses, to treat gout. It’s also used by crop breeders to double the number of chromosomes in plants, because the drug allows cell nuclei to divide without the cell they are in dividing, so doubling the number of chromosomes in the cell - a phenomenon known as tetraploidy. More chromosomes per cell tend to produce larger cells and larger cells lead to larger plants and better crops. All sorts of unnaturally large plants, ranging from some strawberry varieties strawberries to hyacinths, have been bred using this long-standing form of genetic manipulation, which has been in use for over a century. Crossing a tetraploid with a plant with a normal complement of chromosomes produces plants called triploids, with three sets of chromosomes per cell, which are seed- sterile – a common breeding technique for producing seedless fruit.