alexander.kerr

Alright! You got to see the entire decorating process. Hmm thats odd there wasnt a flocculent puff of old silk at the webs centre - the remains of hte old web. Occasionally w my species A. appensa, it falls away on its own and once i saw a little silver thief spider Argyrodes cut it out and haul it away. Or maybe your species does things differently. Will just have to see, i guess.
Re the moulting spider, i think that it was the spider not the mantid that was the lucky one. After moulting shes a softie and so cant bite or fight. Shes lucky the mantid wasnt full grown or i think she woulda been lunch.
Also, in my experience, they only make stabilimenta before they moult, not so much after. Theres a paper by Nentwig who shows the same thing for A. argentata from Panama - so i think its a regular thing.
Re spotting 13, well done. Thats just how its been seen for A. argentata and my species: they always start from the outer hub and lay the arms down while moving towards the centre. A colleague of mine in South Africa sees the same thing with their common species, A. australis. So again i think your observations support that this is proly a widespread behaviour. A. appensa here seldom makes the full X, so that was nice to see A luzona do it. I think what will be really cool is if your species makes a Y or lambda-shaped stabilimentum or the rarest one of all, one consisting of just the two upper elements. What ive seen is they still waggle their backside and go to the bottom part of the web, they just dont lay down any silk before they then go up to the top to lay the upper arm. Curious if your species will do that too.
I have a collection of just about all papers ever written on stabilimenta. Id be happy to send whatever you need, if youre keen. Im here on Guam (we're neighbours!), and my email is alexander.kerr@aya.yale.edu; i can send you a list.

Good luck. One more thing: Some individual spiders decorate alot, some never. Those that do tend to make them in bursts, like before moulting or making an eggsac. Thus, the best indicator that a spider will make a stabilimentum tomorrow is that they made one today.

Hi John B,
Thats a great question. I am close by on Guam, so that time of morning is still dark for me, too. Web building here commences sometime between 0400 and 0500, with a few stragglers starting later. The whole web takes about 45-60 min to make and the stabilimentum if built takes about 30 sec and is installed as the very last step, so its easy to miss. Youll know shes getting close when shes finished laying the sticky spiral. She lays it from the outer web inward until her legs touch the webs centre. Then she stops, goes to the centre, eats the little blob of waste silk from the old web. This leaves a hole in the centre, over which she weaves some silk. Then she keeps up the side to side weaving motion as she walks down to the edge of the sticky spiral, turns, and begins laying the stabilimentum.
I use a flashlight to watch Argiope appensa make their webs. The light doesnt seem to bother them, they just keep on building their web, but i suppose each species might be different. The only occasional prolem is that the light sometimes attracts moths to the web and if ensnared cause the spider to pause web construction to bundle the prey and, if its quite small, eat it. They then return to web building. However, if the interruption occurs during the laying of the stabilimentum, she may not finish building it. So for example, she may only build a short upper arm when, had she been undisturbed, she might have put in a longer one.
Hope this helps. Lemme know how you go. After a few days of getting up at 0400 youll soon see why literally no one has ever bothered to observe how the stabilimentum are actually constructed! lol

Great observation John B. Ive watched Argiope appensa make their stabilimenta, which they usually make around 0430 to 0500 h in the morning. They always start from the bottom, working their way to the centre. Then they walk over to the top and write another arm of a diagonal, also from the outer portion to the central part. So, it would seem that your spider made the neat lower portions first.
Your notes on discontinuous stabilimenta is also interesting: They make each diagonal separately and so can i guess decide whether each one or both will be continuous or not. I hope youll continue observing Argiope and get to see them construct them early in the morning.

This is a new record for the Philippines. The species is Argiope chloreides. The key paper is
https://www.jstage.jst.go.jp/article/asj...