Dale Fort Blog Contents 1 – 34

14 03 2014

Dale Fort Blog Contents

Number 1

All about nematodes


Number 2

3 You Tube clips:

Starlings at Mabesgate

Error Bars in Excel 2007

Measuring Heights on Seashores


Number 3

The History of Dale Fort part 1 (all about the rocks)


Number 4

The History of Dale Fort part 2  (the construction  materials of Dale Fort).  Far more exciting than it sounds, you won’t want to miss it, go there NOW


Number 5

Sargassum muticum in Britain (with a video on how it makes babies)


Number 6

The History of Dale Fort part 3, The First Humans


Number 7

Silverfish and their ways


Number 8

The fat-bellied book chewer


Number 9

Seaweed research at Dale Fort


Number 10

Wormhole research at Dale Fort


Number 11

Limpets and their mysterious ways


Number 12

Anne, Bridget, Cadoc and David


Number 13

St David and his friend Elvis


Number 14

Dancing bananas:  Just how many are there?


Number 15

Six-legged female vampires


Number 16

Cry Havoc!  And let loose the dogs of accountancy………The History of Dale Fort part 6


Number 17

Wee timorous beasties


Number 18

A magical island where strange events take place


 Number 19

The many faces of the mean (and by the way Bill, smoking is neither big nor clever)


Number 20

Deviant Beards and other exciting topics


Number 21

Welsh in 10 Minutes (ddim yn rhugl)


Number 22

Halloween Special.  Read it with the light on……..


Number 23

Back to matters more prosaic but useful I hope.  How to get a quick frequency distribution histogram out of Excel 2007


Number 24

Spectacular weather, huge waves, the demise of a bridge, the scaring of a photographer and much more


Number 25

BARNACLES  so much more than just the worst part of a keel-hauling


Number 26

NUNZILLA makes her debut:  She knows about seaweeds, she’s a nun, she’s clockwork, she breaths fire.   What more could you want?  More history, that’s what and you’ll get it in Blog 26


Number 27

TARDIGRADES…….No it’s not a Norwegian swearword.  Their common name is water bears and they are astonishing creatures.  Read about them and then construct your own with our free build your own tardigrade kit.  Ordvykejys….now that’s a Norwegian swear word.


Number 28

House Dust Mites…..I realise that it would be hard to top the spacetastic subjects of the previous blog but house dust mites are still extremely interesting creatures that eat human flesh and give you allergies.  Read all about them here.


Number 29

WOODWORM All you could wish to know and probably more about about the unsung heroes of the Anti-Furniture League


Number 30

Spider Blog,  Spider Blog,   Does whatever a Spider Blog does…..


Number 31

The History of Dale Fort Part the Eighth.  200 years in 1200 words, suitable for home freezing.


Number 32

Red and yellow and not pink and green, orange and not purple and blue……..seaweeds and light


Number 33

Rocky shore monitoring at Dale Fort Part 1.  Channelled wrack and rough winkles have rarely been given so much attention and for so long.


Number 34

Rocky shore monitoring at Dale Fort Part 2.  Species diversity, small winkles, limpets, barnacles and purple topshells.  Possibly more than you ever thought you wanted to know about these fascinating creatures



Dale Fort Blog Number 30

14 03 2014


There are 40-odd thousand species of spiders in the world

Here is some interesting stuff about three common British species:


The common house spider

Many years ago when I lived at Dale Fort, my colleagues and I would while away the long summer evenings (after we’d finished teaching at 10-o-clock) by lounging about in the staff veranda discussing hypothetico-reductivism or Fiebleman’s principle of additional properties with increasing complexity of structure or whether it was worth walking down to the pub for a proper drink or could we face another dose of Miss Rapson’s home-made apple wine.  On this particular evening we decided on the last option.  After a couple of glasses it didn’t seem so bad and several people had joined us, a jolly evening began to ensue.  Then someone glanced at the wall behind the sofa and emitted a piercing scream.  Everyone looked at where she was pointing.  I have never seen a room empty so quickly.  The biggest spider I have ever seen (outside of a zoo) had emerged from behind the sofa.  It was a common house spider and it was unaware of its effect on us humans because it too seemed scared and scuttled behind the clock on the wall.  You could hear its feet clicking as it ran and I swear to you that I could see the clock pulsating against the wall.  It was HUGE,  at least 10cm across and we never saw it again.  I can only assume that it either died or left Pembrokeshire to begin a successful arm-wrestling career.  The point being that these spiders can become very large.  Avoid arm- wrestling with such massive specimens since they might win and what’s more they can inflict a powerful and painful bite (although they are not poisonous).House spider

Their prey items are things like beetles and earwigs. This species is most common spider to find in your bath.  Usually it’s the (longer legged, smaller bodied) males that get stuck in the bath because they go out on the pull looking for females (or prey) at night and after falling in can’t get out. They stay with the female after mating and after they die the female eats them.

In 1930 a policeman stopped the traffic on Tower Bridge to allow a large specimen to cross the road unsquashed.

They are said to cure the common cold if swallowed alive but this is not recommended because clearly it’s complete balderdash.


The daddy longlegs spider

Daddt longlegs spider

This species has 8 long thin not very hairy legs with black knee-caps and a small round body.  If you don’t like spiders this might be one to tolerate because they prey on the much scarier house spider.  The bite is not powerful enough and the fangs not long enough to penetrate your skin but they inject a very toxic venom which sees off house spiders.  When disturbed they will sometimes vibrate rapidly from side to side.  This is supposed to reduce their visibility to potential predators (e.g. birds, small mammals, beetles, my dog) and thus help protect them. Females carry a silk-wrapped egg bundle around for several weeks and eventually they hatch (30+ babies in my house) to re-infest your bathroom or any room that is not too cold.  They are far more common in southern Britain but appear to be spreading north in recent years, possibly in response to a milder climate.

The money spider

Money spider These are small (up to 2mm) black-bodied and I used to think not at all scary.  Now I  know better.  Recently, a Dale Fort Placement Student refused to enter a room until a particularly scary one was removed.

They usually live in vegetation and spin hammock shaped webs.  They prey on small agricultural pest species like aphids and mites and should be encouraged by gardeners and farmers.  There are over 600 different kinds and they spread about by spinning a long thread of silk which catches in the wind and carries them away.  It’s not known how far and it must be very variable but some reckon up to 100 miles.  If they come into your house it’s probably because they were attached to your clothing or they blew in.  They are the one kind of spider that hardly anyone (except Hayley) is scared of and they are said to bring luck (in the form of money obviously) to the person that they inadvertently use as transport.

Despite their generally benign reputation, The Natural History Museum has a report of them causing skin inflammation when several thousand of them at once bit some building workers.




Dale Fort Blog Number 29

11 03 2014


They are not worms but beetles.  There are many kinds of wood-boring beetles and in common with humans usually it’s the larval stages that cause most trouble.  Often found in houses are the furniture beetle, the death-watch beetle and the powder-post beetle.

larval wood worm

It’s not the adult beetles that eat your roof-frames or furniture, their function is only to reproduce.  After copulation the females lay eggs in cracks, crevices or old woodworm holes in seasoned wood (they don’t feed on living wood).  3 weeks or so later, they hatch and the larvae tunnel into the wood feeding on the starchy parts.  They do this for 3 or 4 years.

When ready to cast aside childish things (like food and tunnels), the larvae move towards the surface of the wood and pupate.  About 2 months are spent turning into the adult form, whence they exit the wood via the small holes most of us are familiar with.  This is often the first time they betray their presence.

adult woodworm beetle  If the sawdust that comes out is a very fine powder the culprit is the powder-post beetle.  Coarser sawdust implies the furniture or death-watch beetles.  Sap-wood (with it’s higher starch and water content) is much preferred to heart-wood.  Some building regulations restrict the use of sap-wood in construction in an attempt to minimise the risk of collapse because of boring beetle infestation.

Death-watch beetles can sometimes be detected by the noise they make which traditionally was seen as a portent of death.  Adult beetles in tunnels bash their heads against the tunnel sides and make a knocking sound (described by Michael Chinnery (in his splendid book Collins Guide to the Insects of Britain and Northern Europe) as sounding like a scaled-down pneumatic drill).  This is thought to be a mate attracting device.  Readers may be familiar with a similar technique used by humans.  Young males in vehicles equipped with huge loud-speakers produce regular thudding sounds, akin to a series of small nuclear explosions that can be heard for miles around.  They believe this will attract mates although evidence that these will be of the opposite sex has yet to be produced.

Edgar Allan Poe featured the animals in his story The Tell-Tale Heart where a man is terrified to death by noises he can’t explain but knows are a harbinger of death.  If only he’d read this blog……

Boring beetles can be killed with pesticides but the chemicals have to soak well-in or they will fail to penetrate the larval tunnels.  If the item with woodworm is small enough you can kill them off by putting it in a freezer set to its coldest.  A dodgy antique dealer once conned an old lady out of a valuable bureau that had a slight case of woodworm.  He placed it in his freezer and disappeared for a few months to cheat some more people while the beetle larvae died.  On his return he opened the freezer to find a pile of firewood.  There had been a power-cut and the freezer had defrosted.  The desk inside soaked up the water and became soggy.  The power came back on.  The water froze again, expanded within the fabric of the bureau and shattered it into small pieces.  It’s nice to think that these woodworms did not die in vain and let us hope fervently that he got splinters in his hands as he cleared up the bits.

 Do not miss Blog 30.  Even I don’t know what it will be about, this blog lives that close to the edge 

Dale Fort Blog Number 28

7 03 2014


House dust mitesA contented flock of house dust mites graze their way gently across your underwear

Whilst not in the same league as Tardigrades for resilience (see Blog Number 27), house dust mites still manage to be more or less a universal inhabitant of our houses.  Their food mainly comprises the flakes of human skin that continuously slough off our outer layer.  A human loses about a pound of skin a year in this way, so if they didn’t eat it, after a couple of decades you could be wading thigh deep through your own epidermis.

 Eating up the mess we make could be seen as a useful service but there’s a problem with house dust mites and it relates to their rather poor digestive systems.  They have only a simple gut, without a stomach and their food is not digested on a single passage through the tube.  They get around this by secreting enzymes and a fungus on to skin particles.  The fungus helps to digest the food (saprophytic nutrition).  They then eat the little lump of skin and it passes through partially digested.  They then eat it again and again and again.  After about the fourth time they can no longer get anymore nutriment out of it and it becomes reclassified as faecal matter.

house dust mite

These little lumps of mite-poo are very light and once airborne can remain so for hours.  Sitting on the sofa, bouncing on the bed and similar exciting human activities can easily cause up to 15.456 billion of them to be launched into the air.  (Actually I made that last bit up but nevertheless it’s lots and lots).

 They are chock-full of digestive enzymes from the mite’s digestive system.  (Enzymes are the proteins help speed (or catalyse) up the chemical reactions that keep mites and everyone else alive).  Some people are extremely sensitive to them and when they breathe them in the protein digesting enzymes begin to attack their lungs.  Asthma, dermatitis, conjunctivitis and sore throats may result.

Our warm, carpeted, softly furnished houses provide ideal conditions for house dust mites.  They are particularly sensitive to desiccation but find a perfect environment inside mattresses which are topped up nightly with sweat, saliva and possibly worse by their human occupants.  They are known to move up and down the fibres of carpets in order to regulate their humidity.  It is believed by many that the huge increases in asthma and allergies in recent times might be put down to the inhalation of these particles.

   The way around it is to sleep on an impervious mattress, vacuum more or less continuously with a vortex machine or one with a special filter and wash all your bedding and clothing at more than 60OC every couple of days.  Alternatively, you could become a naturist and move into a cave or shipping container or similar. It might be cold, draughty and hard-surfaced but there will be very few house dust mites (no sofas or comfy beds allowed of course).

Look out for Blog 29 which will be extremely alluring in its own way…….