ID a spider plz

[brodar]

Hello, i'm a new member and have come across a spider living in my garden (Canada)
the picture is the best i can do with the camera i have at the time and it is on it's web in the picture the white behind it looks like a build up of silk it sits in the same spot every day facing down all the time

thank you



this is temp. url i have loaded to my Gallery and waiting approval

[Ukwildlifeo]

I dare say the species in Canada are different to what we find here, although you have many introductions from here. The underside shown in the photo reminds me of a wasp spider Argiope bruennichi. But there appears to 'nobbly bits' on the abdomen from what I can see which reminds me of Argiope lobata found in S.france. So I'd hestantly guess at maybe a species of the Argiope genus. perhaps google image the species I gave you and see if there anmything like it. You could also try the sister form Wild about the world - there a link at the bottom of the page. Hope I've been of some help

[Venger]

Its a Argiope aurantia from the look of it, fairly prominent in southern Canada and the US and down into South America.
The 'white behind' is a build up of silk called a stabilimentum, the uses of which still aren't really known - possibly a warning to birds, and attraction to insects (it reflects UV), part of its defense mechanism, stability, a moulting platform or a mate attractor - it could be all these things!

[brodar]

Thank you all, now i have more to go on than a picture
Can't wait to see what more i can find out with the info you gave me.
I can see it being a warning ,because it sits right in the open during daylight easy to
see from 8 feet and not a scared one either i had the camera 6 inches away on one
picture and note one movement the yellow on its back is like a florescent yellow

[Venger]

more of a warning so they don't fly through the web...

[GRH]

You may want to visit these two (very good) Canadian/North American spider sites...

Spider WebWatch: An open-access, citizen science initiative in North America

The Canadian Arachnologist: Arachnology & Arachnologists in Canada

The former one asks for submissions of records for Argiope aurantia and A. trifasciata (among other species).

Greg

[brodar]

Originally Posted by Venger

more of a warning so they don't fly through the web...

Thank you again Venger, i have read in other sites that the heavy silk strip they
make in the middle where they sit is also to avoid birds from flying through
tricking the bird to think there is a branch there or something.
good to know though i have never seen one like this in these parts and my mother
in-law has lived on the farm for many years without seeing one like this

thanx for the links i will take a look