s

I am sceptic about this one being Argiope aurantia. Certainly an Argiope sp., but I would rather say Argiope argentata or Argiope blanda. However, Argiope blanda is obviously extremely rare and is only found in the southern most parts of Texas, like your location! But the pattern of the underside makes me more think of Argiope argentata, whereas the markings on the legs are more the one from Argiope blanda.
http://bugguide.net/node/view/413451
http://bugguide.net/node/view/324734/bgp...
http://www.bio-nica.info/Ento/Arthro/ARA...
Argiope argentata is the most common Argiope and is unfortunately very variable.
http://bugguide.net/node/view/736082/bgp...
Personally I tend to Argiope argentata.
http://bugguide.net/node/view/967242/bgi...
http://bugguide.net/node/view/736082/bgp...
http://bugguide.net/node/view/435985/bgi...
http://bugguide.net/node/view/338600/bgi...

This is an argiope of some sort. You can tell from the stabilimenta in the web.