Wednesday, September 5, 2012

The saga of the golden orb weaver egg sac

I am waiting eagerly to see if the golden orb weavers emerge again this season. It's a real mystery what is going on. The summer of 2011 brought an influx of golden orb weavers such as the town had never seen before. Last year, there were none. As spring is springing, the obvious question is: will they return? And why weren't they here last year? One theory is given below. This year will tell if it's right! And the other mystery - how did the daddy long-legs know about the feast on offer?

First, a recap. When we moved to Castlemaine in Central Victoria, Australia, in April 2011, there was a glorious adult female golden orb weaver (Nephila edulis, family Nephilidae) at the front door to greet us. So she was named Welcome.

(click to enlarge)

With a body length of over 2 cm, she was huge. Not long after, Welcome produced a golden egg sac in the bushes nearby. It was already well into winter.

The first frost came and the morning sight was welcome dropping from her web. She recovered in the day's warmth, but the next day's frost killed her.

I watched that egg sac, checking it every day. Nothing happened throughout the whole winter. Up in Kalimna Park, where I was watching another half dozen Nephila, three made egg sacs, and all disappeared with the frosts. 

Now, Welcome had spun her egg sac in the wire on a garden arch which was in the wrong place for my garden design. To move it would have wrenched the egg sac from the plants, so I carefully cut the wire and placed the egg sac on the little front porch. Didn't think that through, did I? When the young hatched, they would use the breeze to disperse - and there's only one way the breeze could come into the enclosed front porch - from the front, carrying them nicely straight into the living room. This is what happened:

The egg sac had faded when I cut it lose in September 2011 and placed it on the porch. It was not until early January, in the summer heat, that I noticed a living bundle near it. Young, hundreds of them. I tried counting from the image below, but gave up.

Over the next few days, they spread and regrouped continuously, little white bodies appearing in the mass of brown as a mess of tiny shed skins appeared below. They were moulting, the slightly larger freshly moulted young showing off their beautifully marked white abdomens - only visible when I enlarged the photographs.

At the end of the week, they were well spread, never to regroup again.

A day with a light breeze and they dispersed on their tiny filaments of silk. It was then I realised that I was an idiot. They could only be blown into the house as a breeze doesn't come from the house out into the world. And they did - hundreds of them into the living room. All over the furniture. All over the ceiling. While they were still in groups, I collected them on brooms and other soft objects, leaving them outside to disperse again. But they spread, meaning it was a matter of collecting them one at a time. They were all over ornaments, such as this little one on the cage of a music box with toy songbirds.

But I was not fast enough. The greatest mystyery of all: within a few hours, five daddy long-legs spiders (Pholcus phalangioides, family Pholcidae) had gathered in the front corner of the lounge room where most of the young landed. I have no idea where they came from. We have a lot of daddy long-legs, but there were none in the living room that I had noticed. The daddy long-legs were having a feast. How did they know to come?

Spiders never cease to amaze and entertain me.

So now I wait. None of these young grew to adults during that summer. Despite the huge numbers in autumn 2011, there were none last autumn (March / April in Australia). Will any of them appear this season? 

Note on the confusing daddy long-legs critters:

An American reader has asked about the daddy long-legs in the photo above. Is it a spider or a non-spider harvestman?

Two different groups of animals are called daddy long-legs, the spider version and the harvestman version. Both have eight long spindly legs. Both are arachnids. I gather Americans are more likely to call the spider version 'cellar spiders'. 

The differences: spiders have two body segments with the legs coming from the front bit, the cephalothorax. Harvestmen only have one body segment.  The spider version make webs while the harvestmen don't. Spiders are much more likely to be inside the house than harvestmen. I photographed huge harvestmen in Texas.

If you look at the image on the blog, you'll see the daddy long-legs has two body segments while the harvestman above has only one. Because of the confusion, arachnologists usually refer to the spiders as pholcids and don't use the 'daddy long-legs' common name.


A great reference for Australian spiders is being developed at

This site is a working draft for "A field Guide to the Spiders of Australia" by Robert Whyte and Dr Greg Anderson for CSIRO Publishing due to be published in 2014-15.

I'll be using it as my prime site for classification from now on.

Postscript: Greg Anderson has sent me a fascinating paper on Nephila. It seems the questions I am asking about N. edulis are not answered - yet! Plenty of research to do which can be done by ordinary people out there watching them. 

"Given the large number of studies that have focused on the behaviour and evolutionary biology of Nephila spp., it is some- what surprising that little work has been undertaken on their population biology. In the Sydney region, adult female N. plumipes are univoltine, appearing in late December to February (depending on the year), and reproduce from late summer to autumn (February–May) (Austin and Anderson 1978; Elgar et al. 2003a). From June to September (winter–early spring) the population comprises a range of immature size classes, and a declining number of adult females that have all disappeared by August–September. This pattern becomes more complex in the northern, tropical part of the distribution of N. plumipes, where the breeding season is more prolonged, and populations may be bivoltine (A. Austin, personal observation).

Far less is known about the population biology of N. edulis, which occurs throughout the arid interior of the continent (Fig. 87). In arid regions this species appears to have more tran- sient populations, where dense aggregations of adult females will occur at a particular site in one autumn and then disappear, often for many years (A. Austin, personal observation)."

Reference: Harvey, Mark S., Austin, Andrew D., & Adams, Mark. The systematics and biology of the spider genus Nephila (Araneae: Nephilidae) in the Australasian region. 
Invertebrate Systematics, 2007, 21, 407–451


  1. This is awe-inspiring, and a little bit funny, as you ended up with lots of spiders indoors, an event a spider lover like me finds wonderful. Finding out there is little or no research on a particular species is exciting, especially when one favors that species. As for the Daddy Long legs, I wonder if somehow scent is involved. Much of what spiders do is unknown, and that too, is exciting.

    1. Thank you, ZBra. I am now back into blogging regularly as the season starts here. I can't wait to see if we get any Nephila this year.

      Spiders are such amazing fun - and it is all there for free for anyone who just takes the time to get to know them!

    2. Oh, and as for the scent attracting the daddy long-legs, that seems logical given they have chemical sensors in their hairs. But the juvenile Nephila are tiny, and the daddy long-legs must have been at least ten metres away, or I would have noticed them. You don't usually get five of them in close range. How strong is their scent detection? I have no idea, and doubt others do either. I'll check the gospel, Foelix's 'Biology of spiders' but I have read it thoroughly and certainly got no indication of long range scent detection. More research to be done.

      I do adore watching a daddy long-legs pair on a web strumming out signals to each other. Is that language?

      Thanks for your comment!


  2. I have enjoyed this read very much. I am an huge fan of spiders though must admit I know little about them. Will be sure to return regularly, thanks for sharing, Jilly

  3. Delighted to meet you, Jilly. Thank you so much for your comments. I look forward to more!


  4. Hi

    This is interesting and terrifying. I have a garden spider across my front door and just saw the egg sac. You think I can safely move it before they hatch in the spring? I can avoid my front door for a few weeks and let her stay, but not for 8 months, and not when there is a spider explosion...(from Mississippi, USA)

  5. The more you watch, the more they just become interesting and the terrifying goes.

    I am not sure what you mean by 'garden spider' in Mississippi, but the orb weavers tend to die before winter. You can move the egg sac, but maybe wait until she has gone? Although, if it is a hassle, you can move her too. Just move part of the web and attach it to somewhere less obstructive. She will probably fix it up there rather than putting it back where it was.

    All the best with it! Thank you for caring for the spider!


  6. Thanks! They call them garden spiders here (among other things). She gets to stay, and I will wait til she dies to move the egg sac. I suspect there may eventually be other egg sacs since she eats a lot. We have Argiope aurantia here, at least that's what she appears to be. Thanks!

  7. Ahh - Argiope, wonderful! I am jealous. Have fun watching her and then waiting for her spiderlings to hatch.


  8. We have an Argirope aurantia in our back yard now. She came to us as an adult rescue spider. The family where she had been living called her HellSpawn, and the dad was going to try and poison her with WD--40. She had built her web across the shed, so she was not in a good place, and the family was afraid of her, which was worse. My daughter asked if she could take her home, and the family agreed. M caught her in a box and we release her in our backyard garden. Within a day she had made a lovely large web in a perfect place -- that was 3 weeks ago. She has caught a lot of bugs and my girls feed her grasshoppers from time to time to see her amazing spinnerets at work. She up, then disappeared today up by the eave if the house. We just checked in her now, and she has greatly deflated. Where she had been hanging by the eave we see an egg sac :) so That's what she was doing :)

    1. What a great story! Thank you! Please tell your daughter that i think she is a hero!

      Spiders are the best free entertainment (and education) in the world.

  9. I just shared your comment with my daughter and she is very proud to be a Spider Hero :) We just came from the backyard where our Argirope has caught a grasshopper that is larger than her body. She is liquefying him now. Yesterday we learned a new thing: spiders can also eat prey whole. She caught a midge, and wrapped it lightly. We were wondering how she would liquefy it and the answer was she didn't: she crunched him up whole, like a taco. Just when you think you know your spiders, they surprise you!! :)

  10. Hi Steve,

    I am so pleased that your Argiope (is that her name as well as her genus?) is providing so much free and educational entertainment.

    I think your new conclusion about eating food whole may be in error - or you are discovering new spider facts and your daughter needs to do a science project on it! Spiders will crunch up prey sometimes, but they still liquify what they are going to eat. They can only take in liquid and filter it finely as it goes into their mouths.

    Are you getting plenty of photos? If so, please send me an email to l.kelly @ (without the spaces). I'd love to see her and your daughter!


  11. I work at a University in NW Florida and I have a beautiful female that lives right outside my office. Today she laid her egg sack!! I'm so excited I could burst! But I can't find any information on what happens to the female after she lays the sack, the general timeframe for the sack to hatch or approximately how many "grandbabies" I can be expecting. By any chance do you know any of this information?

  12. I forgot to mention, she appears to be a "banana spider" or golden orb weaver.

    1. Hi Mysti,

      It is so good to hear from you. I am so jealous. This sounds extraordinary.

      I found information on the life cycle hard to find, but can tell you my observations. It partly depends on whether you are talking about a golden orb weaver or the yellow and black spider, Argiope, although I suspect the life cycle is fairly similar. Both are referred to as banana spiders.

      A golden orb weaver egg sac is very golden. They are genus Nephila, as in the one above. In Florida, there is only one possible species, Nephila clavipes:

      Is this the spider you have?

      I expect she will then die with winter and her egg sac hatch later, but I am not sure. I would LOVE to hear more from you as you observe it, and see any photos. I would love to do a blog on your spider!

      I submit my next book manuscript this week and then will get back to blogging spiders. I can wait!

      Hoping to hear more!


    2. Hi Lynne..I'm so glad I found your blog, I can't wait to delve into it some more! I live on the Florida panhandle so I guess our seasons are the exact opposite. Since late August I've had the privilege of caring for a beautiful golden orb weaver in my front shrubs. We had quite a few around here but I favored her. I fed her at least 2 grasshoppers everyday so in no time she was the biggest spider of them all. One day at the end of September I went out to feed her and she was super skinny so I figured she must have laid her egg sac sometime in the night. I was sort of sad because I have done a lot of reading on the orb weavers and I knew that meant her time was coming to an end. During the next couple of weeks I kept an extra close eye on her and she remained as lively as ever..also I never could find an egg sac. So I continued caring for her and eventually she became as fat as she was before. Then near the end of October we had our first cold spell, and very windy weather with hard rain. I knew she wouldn't make it. But the next morning I found that she had relocated during the storm higher up in a tree next to the shrubs (about eye level), and I couldn't find any of the other orb weavers. I wonder if she survived because she was so well-fed? Every time we had a cold night or a storm I would go out expecting not to see her and she would surprise me every time. So yesterday, November 18th, was a cold windy raining buckets kind of day, and this morning, she is gone. I never thought I'd be sad at the loss of a spider but I found her so amazing, therapeutic to watch, even. I see her egg sack now, under a leaf that was near her web. I'm not sure if she laid it that first time or sometime after, or if there was more than one sac, or what..It doesn't get as cold here as it does some places, but throughout the winter we will have some freezing weather. I don't see how that sack will survive. Do you think I should try to relocate it? And if so, where would you suggest? Do the sacks survive freezing weather? I'd love and appreciate any information you could give me. I have some pics and video of her but I don't think I can add it to the comment.
      I hope to hear back from you!
      ❤ Poppy

  13. Hi Poppy,

    Thank you so much for such a wonderful comment. Isn't it wonderful to follow the lives of individual spiders?

    I have now sent off the manuscript for my next book to my publisher and can get back to blogging my precious spiders! Your post has inspired me to get back to taking the torch and camera out each night.

    It does sound like your favourite (does she have a name?) has survived because she is so well fed and smart enough to relocate.

    I know all about the sadness of losing a spider. I was devastated when I lost my wolf spider, Theresa, one of the stars of my book. I had taken hundreds of photos of her and she was quite used to my presence. She was part of my daily life. I even watered her when the weather was very hot and dry and she came up to drink the droplets every time.

    The sac will survive, I assume, or there wouldn't be any spiders in the area. I have relocated a scam successfully, but I am not sure if it is necessary.

    I'd love to see the pics and video. Then I can post them as a proper post. Can you send them to me at:

    I am really keen to hear more of the story! Two correspondents from Florida now! Wow!


    1. I'm so happy to hear my comment inspired you! My spider had the most common spider name you could imagine..I just couldn't help but to name her Charlotte, lol. Her tiny boyfriend was George. My husband swears he can't remember a year that we haven't had them on our property so I pray that I have another pet next year. He talked me out of relocating the sac, although I've been so tempted. We had our first cold, cold night and some crazy wind this year, but hubby keeps telling me that Charlotte knew what she was doing. I'm really glad I got some pics of her. I'm going to go through my carousel and find some of the best to send to you. Thank you so much for the reply and I look forward to reading your book!
      Your friend, Poppy

    2. My little garden orb weave is out at night and growing but I cannot find her resting place during the day, even though I now know what side of the web she is coming from. She is so well hidden. I can't deadhead the roses until I find her! I'd hate to prune her off the plant!

      Thank you so much for the videos and photos. I have taken a few still from the videos and will blog about them. Unfortunately things were a bit blurry - but that was because of the wind. How amazing that she was feeding and wrapping her prey in that wind. The silk is so flexible!

      I thought that I could see two females in the images. The males are much smaller, and the one against the blue sky and the one wrapping her prey appear to both be female. They look like Nephila calvipes to me.

      I'll do a blog post about her and Rose and Mysti as well.

      Maybe you can comment on that and tell me more!

      This is fun!

  14. I'm glad to see I'm not alone. We live in Michigan and we currently have a golden orb weaver on the front door of our old farmhouse. It has been in the upper corner of the brick door arch since early October and we are assuming female, so like the family above, we also named her Charlotte. The weather has been changing rapidly and she has, so far, survived strong 50+ mph wind gusts, rain storms, snow, etc. She is rather chubby and has grown on us. We have discussed whether we should bring her in for the winter and take care of her with the intention placing her back on the porch when spring arrives. However, I'm now concerned of the potential for babies. We've never seen a mate, but we are reading they can still lay an egg sac? I feel guilty just letting her die knowing harsher weather will surely arrive soon. I'm also going to call our local U of M Nature Center in hopes they'll accept her if we deliver. Any thoughts or leads to help? Thanks, Rose

  15. Hi Rose,

    It is so good to hear from you. When I was writing my spiders book, I interviewed the guys who did the animation of Charlotte for the film and told them what a huge impact they had on the attitude to spiders. They were delighted by that effect of their work.

    I am afraid that her dying once she's laid the egg sac is the way of the world. I'd be really keen to hear of any alternatives. Your Charlotte is a real survivor - incredible aren't they?

    The egg sac will almost certainly survive. If they didn't, there would be any adults for the following season. I would be interested to know how the Nature Center responds.

    As for the male, they are much smaller that the female. Although in most spider species, the males can live on after breeding, that isn't always the case with golden orb weavers. The female will often eat them after mating.

    I have photos now from Poppy. Would love to see any you have as well.

    Thank you again for writing and please send updates!


  16. Hi Lynne and Happy New Year! I am your third Floridian! I love this post. You have a heart of gold to save all those babies. I am in a situation myself. I took down the sac of my friend who lived between the porch posts this summer (a nephila clavipes), it was on the porch ceiling and would have been destroyed during pressure washing. I took it down on the last day of the year and had it outdoors in a glass year with a breathable lid while trying to decide where to put it. Today the nymphs hatched!! They picked the first freeze of the season!! When I saw they were coming out (at sundown), I put the sac in a shallow dish of leaf litter on a table on the porch. About thirty of them were in the jar but stuck in a bit of condensation. I brought the jar inside and they have all dried off an are trying to exit the jar. Should I put them outside tomorrow even though the high will be about 55F? I am worried they won't survive as it will probably freeze tomorrow as well (predicted low is 35F tomorrow but you never know). Do you have any thoughts for me? I have emailed the local extension office for the university here and set a question in, but an internet search did not illuminate questions on nymph survival in freezing conditions of day of hatching. :( I hope the best for my little friend's babies but am at a loss as to how to proceed.

    best regards, Amye

  17. Hi Amye,

    Happy new year to you and all spider-lovers in Florida.

    What a fascinating story. If I can do my calculations right, 35 is close to freezing, about 1.7 deg C. That is cold, but I am pretty sure they can survive it. I am very keen to know what BugGuide or anyone else suggest. I suspect Nature knows better than we do.

    Unfortunately, the reality is that most will not survive whatever you do. If they do their first moult when all confined together, they will start feasting on sibling stew and most will die anyway. Not pretty!

    Sorry, but my advice is that they need to be free to leave. PLEASE let me know what happens!


  18. Thanks for your response, Lynne,

    I put the dish with the leaf debris and the sac in a tall brown paper grocery bag the garage and the little jar with the others laid on side with opening toward the sac. The garage was a little warmer than the outdoors. Just checked and no one is doing much, littles were still in the jar and no one else has exited the sac. the jar occupants were all on a couple of paper towel pieces so I gently dumped them into the litter by the sac. Maybe too cold for them to move much? It is about 45-50 in the garage. Maybe keep them there until they start to move and then put them outside? I have not heard back from anyone else. No moulting yet.

    I will let you know what happens, a bunch of thanks once again!

  19. Looking forward to the next instalment!


  20. Hi, I'm Edie from Folsom, La. and enjoy my nephlia clavipes, but have only seen one Agriope Aurantia several years ago and no more since. I have eight acres and also more Nephlia clavipes than I can count, but treasure each one. So far I have been unable to locate an egg sac, but will keep looking and would like specific information on how to preserve it over the winter and the best possible release of the babies in the early spring. Most of my females have a male in the web with them or one close by. Thank you so much for all the information you have shared. I lost all I could find the year after the Katrina hurricane, but the population has rallied. Edie Stumpf

    1. HI Edie. Thank you for writing!

      I would adore to have more Nephila than I could count. In fact, one would be nice. We have had almost none in the area ever since the burst of activity when I took the photographs above a few years ago. But we have just had a wetter winter after years of drought, so maybe they'll be back this year. I also hope we'll have Argiope. In both, of course, we have different species but they are very like yours.

      I find the egg sacs very hard to find. I only collected the egg sac because it was attached to a structure which was going to be moved. I think that wherever the spider leaves it is the most likely to be successful. If you want to observe it by moving it, then somewhere outside would be best. Inside would be too dry and warm.

      I am so pleased they have rallied after the cyclone. Please let me know if you find the egg sac, and any other observations.


  21. Hi don't know if you still on here. I have had 4 golden orb spiders in my yard. The females kept traveling around the yard and i was following them with the movements, very hard when they decide to move over night and the hunt begins to look for them all the time. I found 2 sacs of eggs in my tree and didn't think they left anything, but to my surprise while pruning my tree i found them and did a Google search and came to your blog. Thank you for putting up pictures of them so I know what they actually look like. I will be looking out for when the babies do come out of the sac. I have never had any golden orb spiders in my yard before. Only this year I saw the 4. But after the storms we had in the Cape this winter, I haven't found any of them. Cheers Chants

    1. Hi Chantelle,

      Yes, I am still here. Since the Spiders books was published, I became obsessed with the topic of my PhD and most recent two books. But I still adore my spiders as much as ever. I hope to have more time to big here now that my new book , The Memory Code, is out.

      How wonderful to have 4 golden orb weavers. I wonder why they are moving. Mine usually don't do that. It sounds like an adventure to find them each day! It's great that you found the egg sacs. The one in these photos are the only ones I have ever found in my own yard.

      The numbers each year do seem to vary a lot, but I am not sure that any studies have been done which know why. I have asked arachnologists and they all acknowledge that the numbers can vary hugely year to year, but don't know why. They suspect it is to do with weather.

      I have no idea where you are. The Cape could be in Australia or South Africa or lots of other places. Where are you?

      Please let me know what you find!


  22. Hello - I just found your site - I hope you are still blogging? I am in Ecuador and just discovered two golden orb weavers. I leaned a lot about them from your site. But - near the webs of mine are uniquely shaped 'cases' that look a bit like the shields men used to wear in battle in medieval times. I have not wanted to destroy one to find out what's inside. Can you explain what they are?

  23. Yes, I am still blogging. It's just that recently there has been so much reaction to my latest book, "The Memory Code", that I have been writing on my author blog, I have lots of things that I want to write here about spiders I will do so as soon as possible. That includes writing about my golden orb weaver who has kept me company all summer but died with the first cold weather a week ago.

    I have no idea what your little 'cases' could be, because I really have no idea what size or shape they might be. If you have a photograph then let me know and I will do my best but I really only know spiders and then know very little about the wildlife of Ecuador.

    You only have one Golden Orb Weaver in the Americas, Nephila clavipes.

    Please enjoy you're gorgeous spiders while they are still alive. Is

    Thank you for writing!


  24. We have a lovely golden orb living outside our front window. We have watched her grow to quite a significant size! Her abdomen is about the size of a 10c piece.
    We were quite upset to see she wasn't at her web for three days and thought she was gone, but today another has shown up. She's the same size in span, but her abdomen is half the size.
    Could it be her? I thought maybe she went to lay eggs, hence the size difference.
    Would you be able to shed some light?

  25. Thank you for writing, Damon. This is exactly the behaviour when they lay eggs. It will definitely still be her. I have seen this often. I have almost never managed to find the egg sac if there is foliage. They are very good at hiding them. It is also the right time of year for her to grow to maximum size and then produce her egg sac.

    She may not last much longer. Early winter cold will be the death of her. That is the normal. Enjoy her company as long as you can. The eggs will hatch but they won't gain a size to be noticeable until next summer. Hopefully you will get a new golden orb weaver to observe.

    Thank you again - I am so glad you have your pet back again, even if only temporarily.