They have yellow legs. Despite their size, they do not pose much of a threat to humans. They do attack cicadas though. The female dig shallow holes in the soil in which they can raise their baby wasps. They hunt for cicadas.
Cicadas are big and heavy.
The wasps cannot fly and carry their catch very far. They tote the cicada to the top of a tree and then launch themselves and their burden from there. After flying as far as they can from there, they climb another tree and repeat the process. They do this until they get to the nest where they lay an egg on the paralyzed cicada. The young wasp feeds on the cicada, makes a cocoon and over winters until next year.