Gasteracantha hasselti was created in 1837.
Gasteracantha cancriformis was created in 1758.
Gasteracantha falcicornis was created in 1873.
Gasteracantha sturi was created in 1857.
No- they eat rodents !
Possibly some species of gasteracantha or micrathena.
The gasteracantha cancriformis is a type of spider known by many different names including spiny orb weaver, jewel spider, and smiley face spider. The bite of this spider causes a burning sensation that is often described like that of a fire ant bite. However, besides the burning sensation the bite is not dangerous in any other way for most people.
Spiny orb-weaver, Gasteracantha cancriformis
The Red-back spider (Latrodectus hasselti) is commonly found in Australia. They are a small black venomous spider with long thin legs, and the females have a red stripe on their globular abdomen.
Arachnid, or 8 legged animal, scorpions are arachnids too.
The Redback Spider (Latrodectus Hasselti) is a particularly venomous spider. It is quite recognisable because of its distinct red line on its black body, and is of the spider genus Latrodectus, in the family Theridiidae. They are usually found close to human residences. That's all I think you need to know. And that you need to keep away from them.
The spider you are describing is likely the Spinybacked Orbweaver (Gasteracantha cancriformis). This species can be found in Florida and is known for its distinctive green and orange coloration. It is a small species of orb-weaving spider commonly found in gardens and wooded areas.
Gasteracantha elipsoides is somewhat close to your description, but I'm not sure if it is the same. Gasteracantha elipsoides usually has six spikes, usually reddish.