# Tegenaria gigantea Egg Sac Construction



## TheTyro (Nov 19, 2009)

My tegenaria female surprised me with an egg sac. I had returned home after a night out to dinner and a movie and noticed a uniquely angled and "softer" bit of silk in her cage, with her standing over it. I suspected it was something special but didn't really seriously think it was the base of an egg sac. I left my room, returned after about half an hour or so and she had already deposited her eggs and covered them in a light layer of silk, as seen here!





I decided to take photos as she progressed. I've never seen any spider build an egg sac before so I was extremely excited.





Nice and smooth covering, well after she " plucked and pulled" and fluffed the silk over the eggs, kind of how I saw a wolf spider in a video doing.





Gathering clumps of dirt and pine needles. I'm glad I had that in the bottom of her cage, I had no idea she's be using it.















She was very picky about the placement of the dirt and pine needles. She'd lug a chunk up onto the silk, stick it on, "glue" it down, grab another chunk and stick it on somewhere next to it, or where silk was showing. Then she'd amble back down or tug-o-war with some she found on her web, and then decide that a piece of dirt somewhere on the sac was not to her liking, yank it off and drop it down again. I have never seen a spider literally tugging with something before, I worried that it was "exhausting" and straining for her...and I imagine it probably was, as she died three days later. 





But not before leaving me with this! 

And for big clear photos of the momma spider, click this: http://www.arachnoboards.com/ab/showthread.php?t=166974


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## jsloan (Nov 19, 2009)

Cool.  Yeah, it's always fun to watch an egg sac being built!  You wonder what is the basis for such complex and careful behavior on the part of the mother.  My _Agelenopsis utahana_ finally built an egg sac last month and she, too, covered it with debris from around her container.


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## Teal (Nov 22, 2009)

*Very cool! Is it normal for common spiders to die after laying a sac?

What will you do with it now? *


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## TheTyro (Nov 22, 2009)

jsloan- I have no idea, I was wondering if there was wondering that myself. I don't think there is any real reason for them to be so crafty. I'm sure there is some logic behind it, and it'd be interesting to find out if there is a very specific reason for doing so. 


Teal- As far as I've read, depending on the age of the spider, most females die soon afterwards. I just took the body ( I had it in the freezer, then put it in rubbing alcohol) to Rod Crawford so he could take a look at it. He said he had never seen gigantea cover the sac with debree like this. It was so cool to meet him and have him confirm her species through a microscope. He even showed us his collection of spiders, butterflies and moths. My mom and little sister were so thrilled.

And he did say it was likely that this specific spider was already an older adult, at the end of her lifetime and that she may have laid several sacs previous to this one. I'm guessing this was the last one she was sending off into the world. He said they usually live a whole year after their first sac. I really like that Tegenaria gigantea has a relatively long lifetime, i'm excited to see how the spiderlings will look. I'll post pictures when they do come out 

Rod also identified a little jumping spider my sister found as Eris militaris. I am so lucky to live near a pro!


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## zonbonzovi (Nov 22, 2009)

Great pic thread!  The web debris is strange- I've seen hundreds of sacs(DIY plumbing), but never one coated with stuff.  Not the most beautiful of true spiders, but a cool captive, nonetheless.  I love the sheet webs & that infamous way of walking they have.  During the summer, we get some beasts building webs between the house foundation, deck & siding.  They have a particular liking for crane flies & these weevil-like beetles that fall into their webs.  Tyro- you must live near the Burke?


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## TheTyro (Nov 22, 2009)

zonbonzovi said:


> Great pic thread!  The web debris is strange- I've seen hundreds of sacs(DIY plumbing), but never one coated with stuff.  Not the most beautiful of true spiders, but a cool captive, nonetheless.  I love the sheet webs & that infamous way of walking they have.  During the summer, we get some beasts building webs between the house foundation, deck & siding.  They have a particular liking for crane flies & these weevil-like beetles that fall into their webs.  Tyro- you must live near the Burke?


I live in Renton, so only about a half an hour drive up there! I've never actually been inside the museum, but I'm planning to visit soon.

The beasts you speak of must be gigantea, like this one. I actually think they are kinda beautiful. I wish I had the love for them in my past as I do now...we had absolute leviathans living in our house when we first moved in. Like, legspan the size of my hand sort of big. Had to be a champ of a male, even my dad was nervous catching that one in particular.


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## alexmargaritis (Nov 22, 2009)

nice shots and cool spider!finally she made you proud of her!


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## Bjoern Elksnat (Nov 24, 2009)

G`d evening

For me, its not T. gigantea, only a beautiful but simple Tegenaria atrica...

LG Björni


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## jsloan (Nov 24, 2009)

BjörnE said:


> For me, its not T. gigantea, only a beautiful but simple Tegenaria atrica...


Hi, LG Björni,

Rod Crawford is a professional arachnologist, and an expert on the spiders of Washington state.  If he examined this spider under a microscope and determined it is _T. gigantea_, that's very likely correct.

http://staff.washington.edu/tiso/index.html


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## Teal (Nov 24, 2009)

TheTyro said:


> Teal- As far as I've read, depending on the age of the spider, most females die soon afterwards. I just took the body ( I had it in the freezer, then put it in rubbing alcohol) to Rod Crawford so he could take a look at it. He said he had never seen gigantea cover the sac with debree like this. It was so cool to meet him and have him confirm her species through a microscope. He even showed us his collection of spiders, butterflies and moths. My mom and little sister were so thrilled.


*

Well, that IS how it went down in Charlotte's web  

That's awesome that you were able to take her to a professional! That must have been really neat.

Good luck with the sac! I'm very interested in hearing how it all turns out! *


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## Ciphor (Dec 28, 2011)

zonbonzovi said:


> Great pic thread!  The web debris is strange- I've seen hundreds of sacs(DIY plumbing), but never one coated with stuff.  Not the most beautiful of true spiders, but a cool captive, nonetheless.  I love the sheet webs & that infamous way of walking they have.  During the summer, we get some beasts building webs between the house foundation, deck & siding.  They have a particular liking for crane flies & these weevil-like beetles that fall into their webs.  Tyro- you must live near the Burke?


Just clickin through old stuff, Zonbon you must have some unique Tegens, my females cover there eggs in massive amounts of debris! Here is a picture of mine with an old egg sac behind a newly constructed one to see the comparison of the change it undergoes in the weeks following her making it. http://bugguide.net/node/view/575354 I've seen crazy large egg sacs. Only my captive ones (because I do not use substrate) have nothing on them, and even then, they will sometimes put dead bug parts on it.


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## zonbonzovi (Dec 29, 2011)

Probably just my confusion.  Lots of species living under the house & plenty of short-lived seasonals to add to the confusion although I have noticed that Tegenaria sacs being guarded in the confines of the woodpile tend not to be adorned with litter.  I find that strange as they are intermingled with a lot of Callobius and I would have thought that a camouflaged sac would be safer from predators?


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## Ciphor (Dec 29, 2011)

You probably have a fair amount of giant house spiders, hobos, and grass spiders (_Agelenopsis_). 

_Tegenaria gigantea_ generally suspend their egg sacs, and wrap in silk then debris. They also group their egg sacs into clusters.





The egg sac looks like a thin disc when captive with no substrate, Pretty drastic difference in appearance. Shows that something may be triggering it in the wild however because she does not even use dead bug remains.



_Tegenaria agrestis_ wrap in silk, then debris, then silk again.
In one case, I found the egg sac wrapped in silk, small rocks, then silk under a 2x4 with cut groves.



_Tegenaria domestica_ wrap in silk, then debris. The debris amount is typically much less then _T. gigantea_, but they can still be difficult to distinguish in some cases. I have not seen one yet personally, so this image is not mine.



_Agelenopsis spp._ vary. Some species suspend from a thick strand, then wrap in silk followed by debris. They are like little dirt balls, perfectly round and pretty smooth surfaced. Others suspend against objects.


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## Ciphor (Dec 29, 2011)

*Agelenopsis spp.*


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## zonbonzovi (Dec 30, 2011)

Thanks for posting the photos.  There's a gentleman with SCARABS in Seattle that keeps Tegenaria...he had some long term captives in large containers at Bugblast and the webbing rivaled that of any prolific tarantula webber.


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## Ciphor (Dec 30, 2011)

zonbonzovi said:


> Thanks for posting the photos.  There's a gentleman with SCARABS in Seattle that keeps Tegenaria...he had some long term captives in large containers at Bugblast and the webbing rivaled that of any prolific tarantula webber.


It's why I love _Tegenaria_, they make massive webs! My storage shed is a massive tunnel and sheet system. If you never disturb them, they can get pretty crazy.


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## Espionage2501 (Jan 1, 2012)

jsloan said:


> Hi, LG Björni,
> 
> Rod Crawford is a professional arachnologist, and an expert on the spiders of Washington state.  If he examined this spider under a microscope and determined it is _T. gigantea_, that's very likely correct.
> 
> http://staff.washington.edu/tiso/index.html


I am feeling a sudden urge to drive to Washington! I almost have my Bachelors in Biology and I am considering getting my Masters in Arachnology, Entomology, or Zoology! And am I to believe there is a museum FULL of spiders? It's like i've died and gone to heaven haha


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## Ciphor (Jan 2, 2012)

Espionage2501 said:


> I am feeling a sudden urge to drive to Washington! I almost have my Bachelors in Biology and I am considering getting my Masters in Arachnology, Entomology, or Zoology! And am I to believe there is a museum FULL of spiders? It's like i've died and gone to heaven haha


Rod is the man. That guy has more species awaiting nomenclature then about everyone else combined. Mostly works with money spiders these days. He works out of the Burke Museum http://www.burkemuseum.org/arachnology

The Arachnology Society is giving away scholarships to those willing to study Polymorphism. It is tedious work, but badly needed right now.


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