Spider, Long-jawed Orb Weaver

Find, identify & discuss the insects of SANParks

Moderator: lion queen

User avatar
Jose
Senior Virtual Ranger
Senior Virtual Ranger
Posts: 1374
Joined: Sat Dec 04, 2004 12:06 am
Location: the Netherlands

Spider, Garden Orb-web

Unread post by Jose »

A large heavy orb-web spider, 30-70 mm in size. The abdomen is lobed and yellow with black spots or stripes. It has thin black striped legs. The head is silvery grey. As is the case with many spiders, the female is much larger than male. The female always hangs upside down :wink: in the centre of the orb web. The front two pairs of legs are often held together and forwards, and the back two pairs together and backwards, forming a cross. Their webs are usually built within a metre of the ground.

    A special characteristic of the garden orb-web spiders - although other diurnal orb-web spiders build them too - are the stabilimenta (sing. stabilimentum) in their webs. These are mostly zig-zagged (but other shapes as well) constructions woven of loose white silk. A stabilimentum's consistency is different from the silk in the rest of the web which is formed by the catching or structural threads. The shape and form not only differ from one species to the other, but also between different individuals of the same species. The stabilimentum breaks up the spider's outline, making the inhabitant of the web more difficult to detect, but also makes the web more visible, and thereby keeps larger animals from breaking it accidentally.

    Other examples of theories regarding stabilimenta are: they adjust web tension, they lure pollinating insects by imitating the reflective patterns used by some flowers to attract insects, or that they simply strengthen the web. They might even fulfil all of these functions.
    (Source: Leroy A., Leroy J., 2000)
User avatar
Jay
Senior Virtual Ranger
Senior Virtual Ranger
Posts: 884
Joined: Sun Sep 04, 2005 7:10 pm
Location: Golden Mile,West Coast, CFG

Spider, Garden Orb-web

Unread post by Jay »

These are beautiful spiders with truly awesome webs! Only problem I have with them is absent mindedly walking into a web while watering the garden :roll: it takes a while to remove all the web from your face and hair :lol:
Ofcourse I never remove, kill or use poisons in my garden as spiders are really awfully good at combatting a lot of the so-called pests.
User avatar
Jose
Senior Virtual Ranger
Senior Virtual Ranger
Posts: 1374
Joined: Sat Dec 04, 2004 12:06 am
Location: the Netherlands

Spider, Garden Orb-web

Unread post by Jose »

For the same reason: always be end of the line on morning bush walks! :lol:
If you see a web with a stabilimentum in your garden, would you mind taking a pic for us? I have images but they're all copyrighted.
User avatar
Pilane
Virtual Ranger
Virtual Ranger
Posts: 398
Joined: Fri Jan 14, 2005 8:11 pm
Location: Somewhere in the Bush

Spider, Garden Orb-web

Unread post by Pilane »

What is a stabilimentum ?


Thicker (white sometimes) pieces of loosly woven silk across the orb web. (various patterns- cross shaped. dics, zig- zag lines etc. It differs from species to species)

Functions? Maybe to stabilise web, maybe to make it visible to large organisms like birds (which are not prey) so that they can avoid it. Spiders might use it to hide behind, It might reflect UV light to attrack pollinating insects, to tension/ strenghen the web....There is no hard evidence to what the pupose of stabillimenta really is.
User avatar
francoisd
Distinguished Virtual Ranger
Distinguished Virtual Ranger
Posts: 1415
Joined: Thu Dec 23, 2004 1:38 pm

Spider, Long-jawed Orb Weaver

Unread post by francoisd »

(800x533 - 102 K)
Image
"The measure of life is not its duration but its donation." - Peter Marshall
Instagram: https://www.instagram.com/francois700926/
User avatar
Goronta
Legendary Virtual Ranger
Legendary Virtual Ranger
Posts: 7932
Joined: Sun Feb 14, 2010 5:30 pm
Location: France now and then

Re: Spider ID needed

Unread post by Goronta »

Seen this beautiful spider near Pafuri picnic spot on the road to Crooks cornerbeginning of may 2016
Could you give an ID :thumbs_up:

Image
Carpe diem

2022 jun1st to jul 3rd Shimuwini Shipandani hide (New) Mopani Punda Maria Pafuri Border camp (New) Makuleke Shingwedzi Satara Berg & Dal (New) Tuli block :thumbs_up:
User avatar
Goronta
Legendary Virtual Ranger
Legendary Virtual Ranger
Posts: 7932
Joined: Sun Feb 14, 2010 5:30 pm
Location: France now and then

Re: Spider ID needed

Unread post by Goronta »

I suppose the little guy near the golden orb spider is the male waiting to be eaten :lol: :mrgreen:
Carpe diem

2022 jun1st to jul 3rd Shimuwini Shipandani hide (New) Mopani Punda Maria Pafuri Border camp (New) Makuleke Shingwedzi Satara Berg & Dal (New) Tuli block :thumbs_up:
User avatar
Philip1
Legendary Virtual Ranger
Legendary Virtual Ranger
Posts: 9400
Joined: Thu Jan 20, 2011 8:58 am
Location: Far South in South Africa.

Re: Spider ID needed

Unread post by Philip1 »

arks wrote:I think that's a golden orb spider, Goronta ... but I'm no expert :wink: Very nice photo!

Agree with you Arks. (and the photo) :thumbs_up:
The male is a small thing against the Lady. :)
"Lose yourself in Nature and find Peace!" (Ralph Waldo Emerson)
UNITE AGAINST POACHING...What we protect,
do not let poachers take it away!

Extinction is forever and survival is up to---every last one of us!
User avatar
Snoobab
Virtual Ranger
Virtual Ranger
Posts: 368
Joined: Fri Aug 26, 2005 2:28 pm
Location: JHB

Re: Spider, Long-jawed Orb Weaver

Unread post by Snoobab »

I was once told that the best Karate Instructors are Spider Webs :lol:
john n poppy
Senior Virtual Ranger
Senior Virtual Ranger
Posts: 2159
Joined: Wed Feb 22, 2006 6:04 pm
Location: Middle of England

Re: Spider, Long-jawed Orb Weaver

Unread post by john n poppy »

Does anyone know if the Orb spiders ....the golden orb in particularly ..are poisonous if they bite you...we head to Kruger this April and last time their were spiders everywhere..

JOhn :thumbs_up:
Kruger - 2 weeks March-April - 2024 .
Kruger - 3 Weeks July-August -2024
User avatar
Karin Mitton
Legendary Virtual Ranger
Legendary Virtual Ranger
Posts: 52398
Joined: Fri Jul 25, 2014 10:56 am
Location: Jhb

Re: Spider, Long-jawed Orb Weaver

Unread post by Karin Mitton »

All spiders have venom. The majority of spiders in SA are not harmful to humans, and orb web spiders are mot listed as having any medical,importance.
I don't beleive an Orb web bite will be any worse than a mild bee sting. Obviously people react differently to bee stings,,and that could be the case with bites.

From what I've read, anti-histamine ointments and pills can be used as treatment. Calamine lotion can be used for itching.

I would however be very surprised of you are bitten by an orb web spider.
User avatar
Elsa
Moderator
Moderator
Posts: 40093
Joined: Tue Mar 22, 2005 6:31 pm
Location: Tinley Manor Beach

Re: Spider, Long-jawed Orb Weaver

Unread post by Elsa »

I was listening to a very well qualified field guide chatting just recently and he made mention of how these spiders and possibly others which he didn't elaborate on, had taken a serious decline due to the drought conditions of 2016.
This interested me as I recall seeing very few of them and their wonderful golden webs last year and we were wondering if the drought could have caused this?
Take time each day to be with nature
User avatar
Karin Mitton
Legendary Virtual Ranger
Legendary Virtual Ranger
Posts: 52398
Joined: Fri Jul 25, 2014 10:56 am
Location: Jhb

Re: Spider, Long-jawed Orb Weaver

Unread post by Karin Mitton »

Now that you mention it else, I've also noticed a decline in these spiders. Previously I would see them all over the place, now I am lucky to see a handful.
Post Reply