When Garden Spiders Live Large

by on August 29, 2008

 

Golden orbweaver.

Public domain image from the National Park Service.

 

 

Look in your backyard right now, and there’s a decent chance you’ll see the ornate webs of our local orbweaver spiders. After feeding on insects all spring and summer, banded garden spiders and yellow garden spiders get big and very noticeable in fall, just before they lay their eggs and die.

These common arachnids, both from a large group called orbweavers, are best known for their spiraling webs found in many gardens.The banded garden spider (Argiope trifasciata) and golden orbweaver (Argiope aurantia) emerge from their egg sacks as small, fully formed web spinners in spring. They start building by creating a bridge from a shrub branch or window frame to another point, and, through complex geometric patterns, they create a sticky insect trap. The spiders eat their webs and rebuild them at night, and start catching insects again the next day.

For these garden spiders, creating silk is a specialized process. Strands of silk shoot from an apparatus on the spider’s abdomen called the spinneret and twist together to form a tight thread. Silk can be altered depending on its use: only the silk in the outer spiral of the web is sticky, as this is where most insects will be caught.

Orbweaver Egg Case
Yellow orbweaver egg case. Public domain photo from NBII Image Gallery.

After catching an insect, the spider uses its legs to turn the prey while spinning silk over it. The spider immobilizes its food with a venomous bite (harmless to humans) before dining.

As the spiders grow, male spiders leave their webs to mate. Sitting on the edge of a female’s web, a male pulls its strands, using vibrations to get her attention. Even though they have eight eyes, orbweavers have very poor vision, so vibrations are the most effective tool for communication during mating season. After mating, a female lays her eggs and creates a thick, papery egg sack to protect them.

Keeping the egg sack safe is a precarious business, and the spiders die in winter, so the babies are on their own after that. A mother spider often suspends the sack on her web to protect it from predators, but the web can become damaged and other spiders and insects might take over part of the sack to hold their own eggs.

The spider young hatch in fall, but wait out the winter in the sack before they emerge and start the process over again.

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18 comments:

Terry on November 10th, 2012 at 11:04 am

Got one of these spiders right now over my pond in the back yard. She was sitting in the middle of the web for the past few week now she is large and hiding in some Junipers at the edge of the web. Laying eggs? Time will tell. My wife has asked if it is poisonous, like Black Widows…I don’t know..that’s why I’m here looking them up on the web!

Terry
Hayward, CA

Dan Rademacher on November 10th, 2012 at 12:49 pm

Hi Terry, Hope you found that they aren’t poisonous. Harmless, and they eat lots of bugs, so they’re good to have around in the garden.

nancy morand on October 8th, 2013 at 5:43 pm

Can you tell me if it would be wise to try and protect the
Egg cases for the winter and how should I do it ? Mama was here in my garden
for 2 months and ladt night astorm damaged her web
and she is now gone. SHE MADE TWO EGG CASES !
Im in Connecticut and we have hard winters somrtimes.
I want these babies to make it.
Thank you for your expertise.
Nancy

Eric Simons on October 9th, 2013 at 3:20 pm

Hi Nancy, I think they should be fine on their own — these spiders are pretty good at managing without intervention! Keep us posted in the spring.

NancyMorand on October 9th, 2013 at 8:55 pm

Eric- A HUGE thank you from across the continent !! I appreciate your expertise on these gorgeous
Spiders. Here’s to lots of babies come spring !!
Nancy

Gene Bray on July 22nd, 2014 at 8:01 am

Does anyone know of a source for purchasing Golden Garden Spider egg sacs?

Bay Nature staff on July 23rd, 2014 at 2:12 pm

Hi Gene,

Unfortunately, we don’t have information about this. Perhaps a garden center like Berkeley Horticultural Nursery might be able to help you. Best of luck in your spider sac search!

chuck on August 27th, 2014 at 9:48 am

I know the spider dies in the winter has anyone brought the spider inside and release in the spring? We were thinking on putting her in our greenhouse for the winter in all our plants to try and save her? and leave the 2 egg cases outside?

Mitxh on September 12th, 2014 at 12:14 am

I have been feeding one for weeks and after an especially big juicy black cricket ( took her all night to eat it) I brought her inside. It has been four or five days now and on the second day she layed her eggs. I noticed she was tiny compared to what she was so I gave her another jucy cricket but she wont eat. I was on here trying to find out if they ate after laying eggs then decided to share. So I guess I am now going to hold on to the eggs till the first day of spring and then take them outside. We will see. I just wantes to watch the cycle looks like i have a few months to wait.

Mitch on September 12th, 2014 at 12:19 am

Gene,
I may take a couple more in over the next week or so. If you are ever in the indiana area I would be happy to share a few egg sacks, if possible.

Mitxh on September 12th, 2014 at 12:21 am

I have been feeding one for weeks and after an especially big juicy black cricket ( took her all night to eat it) I brought her inside. It has been four or five days now and on the second day she layed her eggs. I noticed she was tiny compared to what she was so I gave her another jucy cricket but she wont eat. I was on here trying to find out if they ate after laying eggs then decided to share. So I guess I am now going to hold on to the eggs till the first day of spring and then take them outside. We will see. I just wantes to watch the cycle looks like i have a few months to wait. And would be happy to share with anyone in the Indiana area if possible.

Catalena2 on September 19th, 2014 at 6:14 pm

I would love to know if anyone has had success bringing this awesome spider inside for the winter months. Is it possible for her to last multiple years?

Magma on September 28th, 2014 at 4:48 pm

We have 4 spiders with 5 egg sacks in our garden! Wow! When will the egg sacks birth the babies?

Alexa on October 14th, 2014 at 2:54 pm

I had 3 spiders in the bushes outside of my front door. I noticed the biggest one went missing, then the second one went missing a few days after. Now there is only one left. I noticed 2 egg sacs over the weekend. I actually miss them!

Stephanie on October 20th, 2014 at 5:48 am

I had the same question as Nancy regarding protection of the egg sac. I’m in Texas, so not the harshest place, but we are predicted to have another bad winter like last year. I was away from home for a couple of months. My Hubby said he had seen her just two days before my arrival. Like Alexa, I miss her. She was an awesome “wasper”. I can see her egg sac. I don’t want to move it, but was thinking of putting up something just to block the coming north winds.

jacque on November 8th, 2014 at 9:08 am

you guys are awesome for trying to help out these webweivers! Just wanted you to know …long island ny ps had a yellow one on my deck in aug -2012 right before hurricaine sandy hit oct. 26th it made a very cool web iv never seen before..it was huge ,legs included maybe a lil bigger than a half dollar.and the web had a thick strip going threw the rest of the web..it made the web between the posts on the side of the deck.very cool spider,i acualy wasnt afriad of it lol

Bay Nature staff on November 8th, 2014 at 2:19 pm

Thanks for the kind words, Jacque – and for not being intimidated by the orb weaver who made a home on your deck!

alicia on November 17th, 2014 at 2:25 pm

Hi, I have one of this spider, for a month I being watching at her, my husband an I feel bad seeing her outside in cold weather, so we seaside to bring her in, today I see her building her egg, amazin . I am a person afraid of spider, but this one just catch my attention. My cuestion is, it is danger to keep the egg inside home or have to let it be outside?

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