Backyard Biology

Nature stories from my backyard and beyond

Nature Stories
harvestman

Urban Legend
the real Daddy Longlegs

November 3, 2010

As a young child, one of my first nature friends was the Daddy Longlegs.  I would spend hours playing with these gentle delicate creatures.  No matter how many times I would pick them up, prod them, make them walk on my hand, they always seemed to put up with me, recognizing me as a gentle giant, perhaps a little clumsy in a childish way, sometimes not recognizing my own strength, but one that meant them no harm.  At least that is how it seemed to me since they never bit me as a way of telling me to back off.

So imagine my surprise when a young child told me a few years ago that the daddy longlegs was the most poisonous spider in the world!  Since that time, a number of other people have told me the same thing.  Not just children but adults as well.  Seems like I was a very lucky little boy to have survived handling such a deadly creature.

Now, something about this tale just didn’t seem right, so I decided to investigate.  I went back to my childhood friend and took a closer look.  First I counted the legs, an easy job since the daddy longlegs seems to be all legs.  It had eight legs – like all spiders.  Next I counted the body parts.  All spiders have two body parts – the cephalothorax (head and thorax joined together), where all eight legs are attached, and the abdomen.  The daddy longlegs, however only had one body part – the head, thorax and abdomen joined into one unit.  Well, usually one out of two ain’t bad, but in this case it just wouldn’t do.  The daddy longlegs is not a spider.  It is in it’s own group of arachnids (spiders, mites, ticks, and scorpions.) called harvestmen or Opilionids.  There are well over 6,000 different types of harvestmen around the world.

 Continuing my inspection, I picked up my daddy longlegs (carefully this time) and put it under the microscope to get a closer view of its killer fangs.  But –no fangs.  The daddy longlegs has a set of jaws for chewing, but no fangs for delivering poison. 

So the daddy longlegs is neither poisonous nor a spider.  It intrigued me that I should have heard this story quite a number of times in the last few years.  Looking up the daddy longlegs on the web, I find that it is listed as a bona fide urban legend, a story that has no basis in fact but persists among the public anyway.

The daddy longlegs is such a gentle creature beloved by children around the world that it is hard to imagine where this urban legend comes from.  The most common explanation goes like this:  Daddy longlegs is a name given to a few different creatures in different parts of the world.  In England, the cranefly, a long-legged fly resembling a gigantic mosquito, is called the daddy longlegs.  In Australia, the cellar spider is called daddy longlegs. 

Some people claim that the cellar spider is the daddy longlegs of urban legend, the one with the most potent venom in the world.  But not many people know this because their fangs are too small to penetrate human skin.

While it is true that cellar spiders do have fangs and use their venom to subdue their prey, as stated above, no one knows just how potent their venom is. How can we if they can’t bite us?  All I know is that my cellar is full of cellar spiders and they have never posed any danger to me or any one else visiting my cellar.

The daddy longlegs does not need an urban legend to make us appreciate it.    The facts alone are enough to have it deserve our respect.

First there is engineering.  The round pill-like body is carried aloft by 8 hair-thin legs.  In some species, the legs can be 30 times longer than the body, but still no wider than a hair.  The legs certainly don’t seem strong enough to support the body.

Within those thin legs are muscles, blood and nerves, all working together to suspend the body high above the ground.  If you watch a daddy longlegs walk, you can see the legs acting like shock absorbers, smoothing out the ride.  Give the daddy longlegs a little poke and you will be amazed to see how fast those legs can carry them.

Next is sensory awareness.  Daddy longlegs can see.  They have a projection on top of their body that contains two eyes, looking forward and to either side.  Amazingly enough, for an animal whose legs carry it high (relatively speaking) above the surface, they can’t see what is under them.  Often times, you can see them tilt their body downward to get a better look at the ground in front of them.

The legs of the daddy longlegs are covered with sensory organs.  This is especially true of the second pair of legs which are also the longest pair.  They will probe the ground in front of them with these legs; tasting, smelling and touching.

Then there is dinner.  One of the reasons the daddy longlegs can be found pretty much everywhere is that they will eat pretty much anything of a certain size, anything from detritus to dead animals to small living insects.  But, as stated above, they do not use venom, to subdue their prey.  They have a set of mandibles or jaws, which they use to chew their food.

And finally protection.  Fossil records show that daddy longlegs have been on earth for over 300 million years, longer than the dinosaurs.  For such a seemingly gentle creature, they must have some pretty effective ways of protecting themselves. 

Their simplest method of protection is to let go of what they are standing on, fall to the ground and freeze.  This is often all it takes to evade a predator.  However, if this doesn’t work, the daddy longlegs can move surprisingly fast, outrunning its predators. 

The part of the daddy longlegs that is usually first encountered by a predator is a leg.  If a predator should latch onto a leg, the daddy longlegs can simply detach it, leaving the predator with little to show for its efforts.  And to confuse the predator, the lost leg can continue to twitch for up to a half hour. As long as the lost leg is not one of the second pair of legs that are so important for sensory awareness, its loss doesn’t seem to affect the daddy longlegs much.  In the course of time, it will be regenerated.

The last line of defense is chemical warfare.  The daddy longlegs contain stink glands above the first and second pair of legs.  The chemicals these glands secrete are obnoxious enough to deter many predators.  However, since the production of these chemicals is very energy intensive – even more so than regrowing a lost leg, this is usually the last line of defense used by the daddy longlegs.

As an adult, one of my oldest nature friends is the daddy longlegs.  Since it is not the most deadly spider in the world, not a spider at all in fact, I think I might just spend an hour or two getting reacquainted with one.