I have been a bit lax of late with updating the blog, I have no excuse, but rest assured that my New Year's Resolution will be to be a better blogger. It's not for lack of things to blog about, there's been much going on in the bug house of late. Moving has seen the bug house move into our new flat, and there is "technically" a new bug. I say technically because Curly is not exactly new or mine, but she now lives next door to Dorothy so "technically" new.
So as you can see, Curly is another tarantula, a Honduran curly hair (Brachypelma albopilosum) to be specific. She's the little one on the right, the incredibly dashing fellow on the left... Well, you can guess. Curly's around 7 years old and is possibly the most relaxed spider on the entire planet. If you've never held a tarantula before, then Curly is the best one to lose your spider v-plates to.
Other more sad news is that unfortunately Eric is no longer with us, poor little fellow. I have to say that I'm not really sure as to the exact cause of his demise. He's stopped using one of his claws for several months and was becoming increasingly poorly co-ordinated and found eating difficult. I had thought that a moult might be on its way, but searching online forums brought no definite answers. I have replaced him with a very feisty, and possibly gravid female, who has been named Erica in his honour. Look out for the future baby scorpion post!
Also been having an interesting time adjusting the heating of the bug house, but I think I will save talking about that post until a later date... For now, happy new year everyone! Here's to that New Year's Resolution...
Isn't she gorgeous? A brand new, and (if I'm honest)a little bit unplanned arrival to the bug house is this lovely young Mexican Blood Leg Tarantula, Aphonopelma bicolouratum. It has been decided that her name is Penelope. She (although hard to tell gender at this age) is a year or so old, and is a little bit agitated at the moment, as can be seen by the bald patch on her abdomen.
When feeling threatened a tarantula will rub their hind leg across their abdomen and spray a cloud of incredibly itchy hairs called urticating hairs. These can be particularly damaging if they get in the eyes of a threat such as a predatory bird, or a foolish human (see bug-eyed). She's had a bit of a stressful time of it coming all the way in a van from the excellent Two By Two exotic pet shop in Plymouth, and who knows where before that, so I'll forgive her gumpiness.
Not that you could tell that Penelope was grumpy when she went for a little wander on me earlier. As you can see she's fine with handling so will be playing a full role in the Bug Explorers show when the time comes (and the show is completed - the script is written but now needs further refining). It is a bad idea to just buy any pet without much planning, they are a big responsibility. However, she's a stunning and placid species, the sort of spider who along with Dot will be well cared for and help promote the understanding of all bugs. All in all I'm delighted with the new addition.
Back and feeling refreshed after my holidays, I thought it would be fun to have a closer look at spiders. They are found on every continent apart from the silly cold one that everyone forgets about, there are around 40,000 described species with undoubtedly many more to be found. They can be found in trees, in lightless caves, underwater and even in your understairs cupboard... People are scared of spiders, it is a fact that I will not be able to change. However, I'd like to examine why people fear these amazing creatures, and maybe try and rationalise why they really aren't that bad at all.
Arachnophobia, like all other phobias, is by definition an irrational fear. Phobias are irrational, they are not reflective of the actual danger of a situation. You cannot be phobic of, for example, falling off very high things. You can however be phobic of heights. The difference is the perceived amount of danger compared to the actual danger. Falling from a great height is very dangerous, just being at a great height is not necessarily dangerous. Spiders are similar to this, although in their case the perceived danger is vastly out of proportion with any actual peril. Be that as it may, there are many people who will still insist that spiders are horrible and evil and are going to jump on their face and bite their eyes and lay eggs in their brain... This is an irrational fear. Let's look at the statistical facts. Firstly there are no species of spider in the UK that are venomous enough to kill a human. Allergic reactions are possible, and could potentially kill, but there are no recorded examples of wild spiders killing a human in the UK ever. Compare this to the amount of people killed annually by bees and wasps (4, on average) and the spider stops seeming so scary.
But what of all of the terrifying venomous foreign species? Well, again, it is best to look at the facts before judging. The infamous Redback Spider, Latrodectus hasselti, known to many as the black widow spider, is often thought of as one of the world's most dangerous spiders. The reality of the situation is that although 250 people are bitten annually, only 14 people on record have ever been killed by Redbacks. All of these people died before the introduction of antivenom in 1955. Even the spider considered by the Guinness Book of World Records to be the most dangerous in the world, the Brazilian wandering spider, Phoneutria nigriventer, kills less than 1% of people who are ever bitten, and nobody has died since the introduction of antivenom in 2004. Incidentally, the bite of Phoneutrica can also cause priapism in men, which is a justified reason why it has such a dangerous reputation.
So, given that there are very few spiders that could be genuinely considered dangerous to humans it seems strange that arachnophobia is such a common affliction. There are many proposed theories, but none that seem to dominate over any other. Some recent research in the United States suggests that female arachnophobes may have a genetic component to their affliction, whereas some researchers have suggested that arachnophobia is entirely genetic in origin. I personally think that an entirely genetic origin is unlikely, and having had a brief overview of some of the papers, their methods do not seem entirely convincing. The Avatism blog referenced a Steven Pinker idea: that we may be born with arachnophobia but are able to change it to suit our surroundings as we are gradually taught which spiders may be harmful by our family and peers. A Western lifestyle, relatively free from spiders, could result in this fear remaining for all spiders.
I find a genetic origin for fear of snakes (ophidiophobia if you're a connoisseur of phobias) potentially more convincing, simply because snakes are more dangerous to humans than spiders. Even so, they're not as dangerous as an Anapholes mosquito carrying the Malaria parasite. So why not fear mosquitoes? Scorpions kill many more people than spiders do, yet in our minds arachnophobia means fear of spiders rather than their arachnid relations. 1.2 million people died on the roads worldwide in 2004 yet we aren't all dystichiphobic. In my mind there is another factor that is at work suggesting to us our fear of spiders, which operates alongside a genetic component to our fear.
Think about the last time you heard about a spider in the news. Was it good news? No probably not. Here's the most recent spider-based "news story" that doesn't involve hollywood movies or celebrity nonsense from everybody's favourite hate-rag, the Daily Mail. "Husband blows himself up trying to kill a spider with an aerosol" Really? What was the spider going to do? Give you burns resulting in hospitalisation, thereby wasting taxpayers money on account of being a complete imbecile? Unlikely. It is hard to find anything positive about spiders in the media. Even the bastion of learned thinking, National Geographic, shows tarantulas in this video as aggressive, scary and threatening.
At the point around 0:20 the voiceover says, "these spiders are killing machines..." while showing what appears to be a Grammostola rosea, which is the same species as Dot. I've now held Dot, she's very calm and spends most of her time doing very little. If you are a cricket or a cockroach, then spiders are killing machines, if you are a human then they are not. No human on record has ever been killed by a tarantula. Tarantulas only rear up like that and show their fangs if you provoke them, the message is: 'back off sunshine, I've got big teeth.' Statistically speaking they are much safer than dogs. Try and watch the National Geographic film again, but imagining daschunds, labradors and poodles with the same dramatic music booming while the dogs feast upon other animals and the cautionary voiceover suggestively calls them killing machines. It is only at the end of the film that they make any attempt to redress the balance. Every media outlet does it, and not just the commercial ones. The BBC are supported by license payers money in the UK "To enrich people's lives with programmes and services that inform, educate and entertain." (Their words not mine) Yet they still publish articles that play towards people's fears rather than give a balanced view. The 2008 article suggests that mild UK winters mean that "deadly black widow spiders would be our next alien invader." Aside from fact that black widow spiders (Redbacks) have not killed anyone in the last fifty five years, 2009 was the coldest winter in the UK for 30 years. Nice one BBC.
Scaremongering must have some part to play in our irrational fear of spiders. Whatever the cause of your arachnophobia - genetics, lifestyle or media exposure - you have been quite literally brainwashed into it. Nearly nobody has anything good to say about spiders, so its no wonder that so many people hate them. A friend of mine sent me a link to this video recently, which is one of most fun spider videos since this youtube classic:
The highest living permanently resident living thing in the world is a spider called the Everest jumping spider. Spiders have a evolved some of the greatest eyesight in the invertebrate world, and have also developed eyelessness in cave dwelling species. Young spiders can ride air currents and travel hundreds of miles, and males can serenade females with rhythmic sounds and dancing. Crucially, they are really not that dangerous at all. They are worthy of respect and interest, but not fear. Next time you see a spider that is a little bit too big for your liking I have a challenge for you: go and have a closer look. Don't pick it up, don't kill it, don't threaten it, and it will have no reason to threaten you. You might find that confronting your fear shows you just how irrational some phobias can be.
The beautiful photographs from the photo shoot with 9 Little Bees are of such detail that it is possible to zoom right in and have a good look at some of the bugs up close and personal. So, just before I go away on a short holiday I thought it would be fun to have a think about insect (and arachnid) eyes.
So firstly to mantis eyes, which are probably the most advanced eyes of any of my bugs, and some of the best in the invertebrate world. I touched briefly on mantis eyesight in a previous post, mentioning that they have a fovea. You can clearly see the fovea in this beautiful close-up of the P. pinnapavonis mantis, which has been named "Filthy Lucre the Sardinian Diamond Thief" or Filthy Lucre for short. A mantis' vision is its main way of detecting prey and the fovea allows it to resolve an image and actually "look at" things, rather than just detect movement in typical insect compound eyes.
The Madagascar Hissing Cockroach might not have such developed eyesight as a mantis, but it has never held them back. Cockroaches are one of the most successful organisms to have ever existed, they have been around in one form or another for 250 million years, pre-dating the dinosaurs, and will almost certainly be alive long after humans are no more. Their eyes are compound, made of many separate units called an ommatidium. All of the ommatidia together make up the outside eye which can be seen on this cockroach just above his antennae. Each one of these individual ommatidia has a nerve cell attached to the end of it that hooks up to the nervous system, and so is analogous to a single photoreceptor in a human eye, the rods and cones. In this compound eye there would be perhaps a few thousand units sensitive to light, compared with millions in a human eye, so the picture quality is nowhere near as good, but each ommatidia is very sensitive to light, so is very good at detecting movement. It is also thought that Hissing Cockroaches are also able to detect polarised light, which is used to make 3D films work. This might allow them to navigate in their natural environment but their opinion on Avatar is not yet currently known.
The arachnids have a slightly different arrangement when it comes to eyesight, but there is just as much variety in arachnid eyes as their can be in insects. Many arboreal, or tree-dwelling, species have great eyesight and the zebra jumping spider may have the best eyesight of any arthropod. Unfortunately for Dot the G. rosea Tarantula and Violet and Eric the two P. imperator scorpions, they are not so blessed in the sight department. Ground-dwelling species that spend much of the daylight hours underground have little use for an advanced visual system and principally use their limbs and hairs covering their bodies as their primary senses. Eyes are often described by Zoologists as "expensive" meaning it takes a lot of energy to make and run a good eye, so if a creature can get by without good eyesight then it gives it an advantage.
Still, eyes are useful things, and both Dot and the scorpions have eyes situated right on top of their head, ready to warn them if a predator such as a bird is about to attack. Spiders normally have eight eyes, and I believe that tarantulas do too, although Dot's are so small that it is hard to make out all 8 in her picture. As for scorpions, well I have no idea how many eyes P. imperator is supposed to have. There seem to be relatively few sources of information on these less optically advanced arachnids' eyes, except that the general consensus is that their sight is 'poor'. It would seem that many arachnids have both compound eyes like an insect and simple eyes made from a single lens. Incidentally, 'simple' just describes the amount of lenses, not how good the eye is - you and eye have 'simple' eyes with just one lens, but human eyesight is pretty good. From a couple of googles the main priority we have with tarantulas and eyes, even in academic work, is with the potential damage that their urticating hairs can do to human eyes. There is very little work that appears to have been done on how well many arachnids can actually see. Maybe it would be better if we all feared these amazing guys a little less and wondered about them a little more.
It seemed only fitting to properly unveil the new arrivals with some beautiful photographs of a sort that I am not capable of taking. Above is a shot of one of the new Giant African Millipedes, Archispirostreptus gigas. Many thanks to 9 Little Bees for his stunning work I hope you all enjoy the pictures.
Above you can see one of the large male Madagascan Hissing Cockroach, Gromphadorhina portentosa. You can tell this one is a male from the two lumps on the top of his head that he uses to assert his dominance over other males. As the name suggests, they can hiss by forcing air through their spiracles and males like this one tend to hiss more than females.
Giant African Land Snails can be one of three different species which are difficult to differentiate between so "GAL" is the normal catch-all term. This one is a venerable old lady (although actually, snails are hermaphrodites so its both really) who is about 12 inches or so in length when she's fully extended out of her shell.
Finally, we have a personal favourite of mine the Emperor Scorpion, Pandinus imperator. As long as you know what you're doing, they are perfectly happy being handled and are in fact incredibly gentle as long as you're not mistaken for anything edible. As an arachnid, they have eight legs and two 'arms' which are this species' main weapons - its claws. The size of the claws tell you that the sting is not particularly potent, and in fact they rarely use it.
With all the new additions, I've been spending quite a bit of time sorting out all of the critters and making sure they've settled in OK. Once its looking a bit more settled in the bug house there will be plenty more of these stunning photos and lots more all about these brilliant beasties.
On Tuesday Bug Explorers became the home for a whole pile of bugs, including Emperor scorpions, hissing cockroaches, giant african millipedes and more. Check the bug house list for more details Since then, I've been desperately trying to organise them into new enclosures and making sure they're all healthy, happy and well looked after.
They have all been kindly donated by Explore@Bristol as the critters were not getting the use that they deserved among their busy school workshop schedule. The Bug Explorers have promised to get them working a bit more often and will be making sure they're in schools as much as possible. Once everything is ready they will all be given some space on the blog, but for now I must go and clean out a giant African land snail!
Next week, Bug Explorers will expand massively with an influx of new critters that will pretty much complete the collection for the time being. For now, the newest addition to the bug house is a beautiful, fierce and gruesome predator that looks like it has come from another world, a Peacock Mantis, Pseudempusa pinnapavonis.
It may just be because I've just been to see the new Predators film (No Arnie, no point in my opinion) but their heads to bear a striking resemblance to the dreadlocked death-machines from the film. Couple that with a slender, spiky body that could be out of Aliens and they're a sci-fi nerd's dream bug.
It's not just in appearance that these guys seem like aliens, their behaviour is pretty strange too. Unlike other predatory bugs such as many arachnids, ants or centipedes, mantisesrely on sight as their primary sense used for hunting.They are great at seeing movement, like many insects, but also and have a "sweet-spot" or fovea that can resolve detail at a distance of potentially up to 50 feet. Although this is not that remarkable in human terms, for an invertebrate, particularly one with compound eyes it is unusually good. They have good depth perception too, and will sometimes sway like sick insects do to improve this by using parallax, before hitting out with their strong and spiky forearms. Their use of crypsis is like stick insects too, their colouration and shape enables them to blend perfectly into their background and stalk their prey. The cricket doesn't stand a chance, and is eaten while still nominally alive. Twitching at least. You can actually see that the antenna are moving in this picture, and while insects do not have a nervous system like us or pain receptors like mammals and other vertebrates do, you've still got to feel a bit sorry for the thing. That is not to say that other predators like spiders are in some way morally better for killing their prey a bit quicker. Predators kill their prey in a quick and efficient way to protect themselves, not spare the prey's suffering. Imposing human ideas like suffering, morality and pity is anthropomorphism (something I wrote an entire dissertation on) and although these are natural human responses to this issue, they are not scientifically appropriate. How and why prey are killed are interesting scientific questions, but anthropomorphism obscures the science if not used carefully. For a mantis, there is no need to ensure a prey item is dead because there is no escape from it's vice-like grip. For a spider, venom is required to eat because of its mouthparts.
Female mantises are notorious for eating males during or after copulation, which when seen from a human perspective seems horrific. Considered through the eyes of natural selection, however, this must be a successful strategy for mantises. Male mantises provide only genetic material for the next generation, making no further contribution to their offspring. Females that eat their partners get more food than those that do not, so are better nourished to provide a ootheca (egg sac) for the several hundred baby mantises to grow inside. If fact, it could be said that being eaten is the male's contribution to this next generation. Of course, males that can escape their hungry partner can then go and find another females to mate with and so may produce many thousands for fertile eggs, but these females may be under-nourished and so the eggs never survive to reproduce themselves. This is the essence of natural selection; anything genetically based (which can include behaviour) that improves the chances of the next generation's survival will flourish. Female mantises tend to be larger and stronger than the males and so can, if hungry, eat them. Male mantises are also able to continue copulation whilst being eaten (as I said before, their nervous systems are very different from ours). Both behaviours help the survival of the next generation, regardless of how we may regard to view them as humans. Of course, this behaviour would not work in animals that require more parental care from both parents, as is the case in most vertebrates, but it does go to show that nature is not nice, or nasty.
Still, natural selection rants aside, despite being highly successful predators, mantises are prey for many larger species such as mammals and birds. The latin species name of the Peacock mantis, pinnapavonis, literally means "peacock tail", because of peacock-like eye spots on the adults wings that are used as a threat display. This little juvenile is too young for that at the moment, but if faced with danger (in this case being threatened with a biro) they will hop around then collapse on the floor and play dead. Rather than apparent death, or thanatosis, which is found in animals like opossums and some snakes, this is more likely a use of their crypsis as the brown colouration of the body makes them hard to spot. Thanatosis relies more on predators preference for live prey to put them off, although some scientists do consider it a form of crypsis.
It seems that the playing dead behaviour may be more common in males, so I think the mantis may be a he. He is as yet unnamed though, so name suggestions in the comment box please!
A fellow bug explorer found a caterpillar crawling its way around on the floor the other day. Thinking it might be lost, confused or possibly looking for a human to take care of it, the decision was made to find out what it was and see if we could raise it in captivity. A little bit of digging suggested that it may well be the caterpillar of the Lime Hawk Moth, Mimas tiliae.
Mimas tiliae turns out to be a reasonably common species, particularly in the South of England, that is often found on tree-lined avenues. The adult is a pretty cool looking moth that has nice pink markings on its wings, and it seems to be possible to raise them to adults relatively easily. Only slight problem with that is when it comes to lepidopterans (butterflies & moths) both my fellow bug explorer and I know the theory, but are severely lacking in practical experience. Still, never ones to let that stop us, we're going to do our best.
It seems that it's colouration may mean that it was looking for some soil to dig into and pupate over winter. It might take a while, but we'll see if we can raise the little caterpillar into an adult Lime Hawk Moth.
Dot's eating again after her moult, which is good news all round, except I suppose for the cricket, which is now old news.
Asking around on an insect forum called bug nation about when to expect her to start eating again (www.bugnation.co.uk) a nice fellow called David got me wondering about how I knew Dot was a lady spider... Um... Well... The man in the shop said she probably was...?
A little bit more info about Dot is that she was actually a RSPCA rescue spider who apparently came from a man who accidentally let her escape one day and his wife essentially told him, "It's me or the spider." The spider lost. As a rescue she was free to a good home and Josh, the other bug explorer, and I have been sharing her ever since.
But this got me thinking: what do I actually know about Dot? Well, I am sure she's a Chilean Rose Tarantula, Grammostola rosea, from her size (about 2 1/2 inches wide by 3 inches long) I know she is still a juvenile, I also know she's sometimes a little less docile than many people consider her species to be, and that's about it. David from the forum put me on to an interesting and useful article called How to determine the sex of your tarantula. Be warned though, it is incredibly geeky and does feature the line "until my face is bluer than a Haplopelma lividum' s legs!" No, me neither.
Still, from the article and the very helpful people on Bug Nation, it seems that the jury is currently out on the definite gender of Dot. The evidence points towards her being a her, but there is no definitive answer yet. I may still have to turn her name round the other way and start calling her Todd.
Don't worry, no spiders (or people) were harmed in the taking of this photo. Dot the Chilean Rose Tarantula (Grammostola rosea) hadn't been eating much of late. It's apparently not unusual for captive spiders to go off their food, just like they could go for months in their natural desert environments without any prey. But it seems that there was another biological process at work here. Dot was moulting, shedding her skin. Many other animals including humans do this, except with humans its a bit more of a gradual process. Just like all arthropods (arachnids, insects, myriapods, crustaceans and the like) Dot has a tough exoskeleton. It's a good system really, instead of an internal skeleton like you and I have, arthropods keep their skeleton on the outside where it offers extra protection, like a suit of armour, as well as support.
Except what happens when you want to grow? Well, you need a new suit of armour, which means you need to get rid of the old one first. This rather extreme form of moulting has to happen in arthropods because of this exoskeleton and is called ecdysis. It's a rather stressful experience for any creature, as you might imagine. They can also lose limbs in the process and are very vulnerable while they wait for their new skeleton to harden up. Thankfully, Dot's moult seems to have been a complete success.
Dot also relies on her exoskeleton for feeding as well as defence. The sizable fangs you can see are certainly long and sharp enough to pierce human skin and deliver a painful bite, Dot (and all other spiders) doesn't want to do this, insofar as an invertebrate is capable of wanting anything, but that's another debate. Often when tarantulas and other spiders use their fangs in self-defence, they will "dry-bite" and not use any of their precious venom. Spiders cannot eat people, and so unless you threaten them they will basically ignore you. Spiders can only eat liquids, so use their fangs to inject a venom into their prey, digest its innards and suck out the tasty liquefied cricket, fly or whatever it may be. Their fangs are actually modified arms, and so are part of their exoskeleton meaning that they also become completely useless while she moults. That does mean that they will grow as she does. It also means that while she is still drying out, she won't be too hungry just yet, but I'm sure she will be soon.
And if you're still worrying about those fangs, then consider this: of the 40,000 species of spider currently recognised none are able to eat a mammal any larger than a small rodent, and only 7 species have ever been known to kill humans. Of those 7 the deadliest is thought to be the Brazilian Wandering Spider (Phoneutria spp.). Brazilain Wandering Spiders generally kill about 1% of people who are ever bitten. Who's afraid of whom?
Marjorie is a Diapherodes gigantea which doesn't really seem to have a common UK name apart from the "Giant Lime Green Stick Insect." Which is a little bit uninspired.
As you might guess form the "gigantea" part of her Latin name, she has quite a lot more growing to do and should eventually be about as long as my outstretched hand and as thick as my thumb.
The swaying movement that she displays is thought to have two functions: Firstly, as I say in the video to Hayley, she sways in windy conditions to aid her camouflage, or crypsis as it is often called. Secondly, she is using the motion of her head to detect relative movement of near and far objects, parallax. This helps her perceive depth. Clever stuff!
Righty ho, first post. Blimey. Well, these pages are going to feature the bugs that I'm looking after - currently Dot the Chilean Rose Tarantula (Grammostola rosea) and several stick insects which are Macleay's Specters (Extatosoma tiaratum) and Diapherodes gigantea. There'll be lots of pictures of said beasties and the latest of what's happening in their world just as soon as I figure out how to put it all up...
So as you can see, Curly is another tarantula, a Honduran curly hair (Brachypelma albopilosum) to be specific. She's the little one on the right, the incredibly dashing fellow on the left... Well, you can guess. Curly's around 7 years old and is possibly the most relaxed spider on the entire planet. If you've never held a tarantula before, then Curly is the best one to lose your spider v-plates to. 
