Thursday, September 17, 2015

Behind the Scenes with a Black and Yellow Garden Spider (Argiope aurantia)







Watering the plants on the front porch the other day, I turned to see the most beautiful and HUGE black and yellow garden spider in the midst of her HUGE orb web. She was busily reinforcing the center part of it with the customary zig-zag lines that make these webs so easy to spot.  She was most assuredly a “she” because in the world of these spiders, the female is easily twice as big as the male.  Her body is only a little over an inch but her leg span is almost 3.5” so she will definitely catch your eye. 

Unless you live in the Rockies, you have a good chance of seeing one of these beauties, for they are fond of making their webs, as their name suggests, in your garden, or in your bushes probably just a few feet off the ground.  

 They belong to the genus of Orb weavers; think classic spider web with concentric circles, then think of Charlotte and her clever “writing” in the middle of the web. Ergo many people call this spider the writing spider. 
 



The zig-zag lines provide her with a hiding spot in the center of her web and also helps the birds to see it and avoid it.  Here is your word for the day; the proper name for those lines is stabilimentum,  perhaps because they also help stabilize the web.  This lovely web may take hours to build, and yet, each evening, the spider will eat the center concentric part, which is the sticky part and build it anew.  Perhaps that is akin to a fisherman cleaning his nets. 
 
I titled this “Behind the scenes” for the morning I found her she was doing just that, rebuilding the center web.  We had just had a windy rainstorm so perhaps this was an emergency repair, or she simply didn’t get the memo that these repairs were supposed to take place at night.  I stood there watching as she lifted her abdomen and using that third claw that these spiders have on every foot, deftly attached the new web strand to the old one.  In the lower part of the web was a large red paper wasp, trussed lightly in silk for a meal later on.   Being large spiders they can dine on larger insects, grasshoppers and the like, and some have been said to snare lizards. Small ones I would presume.

Luckily , we aren’t on their menu, and if for some reason you did get bit it would be no worse than a bee sting.  Nothing deadly.  A man once brought us a garden spider in a peanut butter jar, wrapped with layers of duct tape to keep this “deadly” spider contained.  He thought he had caught a tarantula! Not likely on the Cape, but then, maybe better safe than sorry.  And as these are great spiders to have in your garden, we happily gave it a home in ours.

If you are a male spider, with an eye on a female, then that’s another story.  Who knows to what advantage this is, but for the males, finding that perfect someone is bound to end in disaster.  Plucky little guy will make his smaller web on a corner of her larger one and then “pluck” at the strings of her web to get her attention.  However, like the hapless black widow male, or the male praying mantis that can’t count on any bragging rights, he mates and then dies immediately.  The female, as we all know from Charlottes Web will also die when the weather turns cold but not until she has made 3-6, light brown, pear shaped, egg sacs which hold the customary 1,000’s of little spiderlings. 


 They may hatch in the winter, but will stay within the sac waiting for spring when, the coolest of cool sights, will be to see them all “ballooning “ on the wind, drifting away from all their hungry siblings!

Sadly, the last few days, when I checked on her, the web was empty.  No prey caught  in it, but no spider either.  No signs of a struggle. They don’t go on a “walk-about” but tend to stay on or near the web so I fear something untoward may have happened to her. So many lizards patrol this same spot that perhaps she has become part of their energy cycle.  It’s the way of the world.  But I will keep an eye out, and keep you posted, for I would have loved to find those egg sacs suspended from the nearby bush. 

I think I will just feel fortunate to have seen her at all, and with such a close up of her spinnerets turning out the silk.  Let us rejoice always!  It surely felt like a peek into the “unseen” I often ask God for.  May your day include the same, the “unseen” seen.




Sunday, September 6, 2015

The Mystery of the Pile of Legs

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I hope that title caught your attention. It WAS a mystery, and it WAS a pile of legs.  Spindly black legs all piled up on the ground beneath a part of the stucco wall that is often covered with legions of harvestmen, (some people call them daddy longlegs).  I find them congregating in various parts of the deck; sometimes they cluster on the stucco wall, other days I may find them all packed into the corners of the ceiling or hiding behind the water tank.  
 
Harvestmen are nocturnal so their roaming about and hunting for food is something I don’t get to witness, although, a night on the deck with a flashlight might be interesting. The gregarious clumps I see are the way they spend the day. Safety in numbers I suppose but they seem awfully conspicuous and I often wondered if the birds ever found them to be a tasty treat.  This pile of legs seemed to be the answer to that.  I had just recently read a nature article about the Hill Country where the author mentioned that he could tell his wrens had had 4 harvestmen for breakfast by the number of legs strewn about his patio!     

Aha! I have several pairs of wrens in the yard, both Carolina and Bewick’s wrens and for the last month a pair of recently fledged Bewick’s wrens have made the back deck their number one hang out.  They have been endlessly entertaining as they land on the clothesline never expecting it to swing, flapping to keep their balance. They also find sleeping in a straw angel hanging on the post not only the best place for them to hunker down but a proven way to startle me each morning when they fly out.  And most recently, they have found underwear on the line to be the perfect cradle for a nap by day.  Discretion kept me from taking a picture of that!  So, it seems to me that they may be the likely suspects.  Not that that would hold up in court.

Of course, the only really edible part of this creature is its one body part.  In Harvestmen, as in mites or ticks, their head and thorax are fused together and called a cephalothorax. Insects have three body parts and spiders have two.  Although they are included in the Arachnid class, that one, not two, body parts earn them their own Order, Opilliones.  (I love the way that word rolls off the tongue, so very Italian sounding)  It’s hard to imagine getting your fill on this one small body part but I suppose if you eat enough of them it must count for something, for it was a substantial pile of legs.

As a defensive gesture they do have the ability to jettison a leg when trying to evade a predator. And that leg will continue to twitch around for a while distracting the would-be-assailant, but this pile had too many legs to have been caused by that.  I am still putting my money on the wrens.

The harvestmen’s other defense is a pair of scent glands located next to their eye that gives off a foul odor, ostensibly to discourage anything making a meal of them.  “Giving someone the stink eye” could take on a new meaning in this context! For that matter, some people think their mass groupings are for the purpose of really putting out a substantial stench when threatened.  I can’t say I have ever noticed an odor, but then I have never seen them being threatened.  When I get to close to them, they all start gyrating and do an impressive amount of push-ups but that’s all.

Once again, where was the camera?  Not with me, and when I went back the next day the wind had blown all those delicate legs away; the crime scene had vanished.   Now I check daily to look for other signs of feasting but so far, no luck.  Which is why I always say, if you see something out of the ordinary in nature, get excited about it now, for you may never see it again.

By the way, the name harvestmen comes from the fact that, in cooler climes, like the Cape, they are most often seen at harvest time.  Here in Texas, they are my year round companions.  Remember, they are not true spiders ergo; no fangs, no venom and no danger to you.  Plus, they have this amazingly wide diet including aphids that you would be happy to be rid of, decaying vegetation and (no accounting for taste) bird poop, so welcome them if they come, your deck may be cleaner for it!