Other Common Names
Golden Orb-weaver (California) - see
forum discussion
Yellow Garden Orbweaver
Writing Spider
Black & Yellow Argiope
Size
female: 14-25 mm
male: 5-6 mm (sizes do not include legs)
Identification
Stabilimentum (reinforced area) in web makes a vertical zigzag band above and below the middle of the web. Juveniles make a circular stabilimentum in the center of the web.
The normal colors are black and yellow
-
Range
Much of temperate North America: southern Canada, through most of the lower 48 states. Also found south through Mexico to Costa Rica. Uncommon in parts of Rocky Mountains, Great Basin.
Season
Noted most in late summer and early fall, when large females are found in webs.
Life Cycle
...which produce masses of spiderlings:
though sometimes they are parasitized:
The immatures camouflage themselves in the stabilamenta, an area of heavy silk:
The spiders, both immature
and mature
hang head down in their webs
which have that familiar zigzag pattern
To grow they must shed their exoskeleton: Richard's fabulous
VJ talks about how they vibrate their webs, testing for captured prey?
Sometimes they lose legs, but can regenerate them:
And then it's time for the cycle to close, with the female preparing her egg case:
Remarks
Despite bright colors this spider is not a danger to humans. It is very unlikely to bite unless severely provoked, and in that case the bite would be probably no worse than a bee sting.
Closeup of palps - male reproductive organs:
Images with male and female for comparison:
Print References
Marshall and Edwards, p. 40
(1)
Jackman, pp. 75-76, plate 9
(2)
Internet References
Animal Diversity Web an extensive article from the University of Michigan
