Pronous (Ancient Greek: Πρόνοος) is a son of Phegeus, king of Psophis. With his brother Agenor he ambushed and killed Alcmaeon at their father's command, then was himself slain by Alcmaeon's sons Amphoterus and Acarnan — or, in some notices, by their sister Arsinoe. He is distinct from the Ithacan suitor of Penelope and from the Trojan Pronous whom Patroclus slew.
Adapted from Wikipedia, "Pronous (mythology)" · CC BY-SA 4.0
I.Son of Phegeus at Psophis
Apollodorus tells that when Alcmaeon returned to Psophis claiming he would dedicate Harmonia's heirlooms at Delphi but carried them instead to Callirrhoe, Phegeus' sons Pronous and Agenor ambushed and killed him. They sold their sister Arsinoe to Agapenor at Tegea, falsely accusing her of the murder.
Callirrhoe's sons Amphoterus and Acarnan, grown at once by Zeus' gift, met Pronous and Agenor at Agapenor's house while the Psophidians were carrying the necklace and robe toward Delphi — and killed their father's murderers. Pausanias names Phegeus' sons differently (Axion and Temenus), so the atlas keeps Apollodorus' Pronous–Agenor fork as this node.
II.Homonyms
This atlas entry (pronous-psophis) is Phegeus' son. Wikipedia also lists Pronoos son of Deucalion and Pyrrha; a Trojan Pronous killed by Patroclus; and an Ithacan suitor of Penelope (pronous-ithaca in this atlas). The spider genus Pronous is unrelated.