Sunday, August 7, 2011

Spiders in your face

Anyone who strolls woodland paths in late summer probably knows all about this type of spider web. It is the creation of the spined micrathena, Micrathena gracilis. These orbweavers have a penchant for building their sizeable silken traps at head level across openings in woods. The proliferation of spined micrathena webs has prompted many a hiker to pick up a stick and use it to flail the air in front of them as they proceed on their journey, batting the webs down before they get a face full of silk.

Next time, before batting the web into oblivion, pause and look in the center. There'll be a funny little object that looks more like a piece of debris than it does a spider. This is the micrathena, engineer of this incredible structure. Unlike many spider species, micrathenas are active during the day and if not disturbed remain on sentinel duty in the center of their web.

If you've got the inclination, move in for a really close look. Spined micrathenas are quite bizarre in appearance, with an enormous humped back armed with several thornlike spines. One theory is that this daunting structure serves to protect the spider from bird predators, who might have issue with trying to consume such a thorny morsel.

If threatened, the micrathena has another trick up its sleeve. Next time you see one, gently tap it on the back with your finger. It will instantly launch itself unerringly and with incredible rapidity straight at your neck, and expertly pierce your jugular vein and drain you of all blood within seconds. Just kidding. What the spider will do is begin a rapid back and forth swaying, shaking the web as if it is bouncing on a trampoline and thus becoming a blur of motion. That stunt may be an attempt to either frighten off would-be predators or perhaps make it harder for them to capture the spider.

If you're really lucky, perhaps you'll walk face first into one of these. Triangle-bearing orbweavers, Verrucosa arenata, also build webs in wooded areas, sometimes in places where one might walk right into them. While not rare, this species is typically far outnumbered by micrathenas.

Another diurnally active spider, the curious-looking triangle-bearing orbweaver also sits tight in the center of its web. Because of that pale triangular carapace, the spider stands out from afar and if you are careful in your approach, you can work your way in for a very close view. Note how the spider hangs with head pointing upwards. This is not the norm; most spiders that hang in webs do so with head pointing downward.

Triangle-bearing orbweavers are truly beautiful spiders. The oddly shaped body can be yellow, cream-colored such as the animal in this photo, or white. This is definitely one to watch for when you are out and about in the woods.

6 comments:

Jack and Brenda said...

Thanks for all the information about these interesting creatures. I got a nice photo of one last week after it retreated onto some dead pine needles. http://www.pbase.com/image/136899249
I have a link to your site below the photo.

Heather said...

The spined micrathenas are plentiful at my place. They outnumber the triangle-bearings by at least 3:1. I try not to knock down too many webs, but, unfortunately, I'm not fond of silk in my face, either.

Wren nests in... said...

Year of the Spider! Add me to the "have micrathena everywhere this year" list.

Except it seems perhaps I'm the only one who has to deal with them in my face on my own front deck... (You'd think she'd have given up by now, but no--she moved from the end of the deck across the secondary set of steps to the middle of the deck. Does this mean she's winning?)

Nice shots! Speaking from experience, it's hard to focus on the little buggers...

Wren nests in... said...

Hah! And I raise you one Arrow-shaped Micrathena!

;o)

Michael Bartneck said...

great post..I ate one yesterday..haha..well not literally! Having lost my near vision due to age, I seem to be a micrathenas web to face magnet!Luckily they don't seem to get mad, at least not yet anyway!;)

Anonymous said...

R they poisonous