They aren't a game fish, so cast netting would be legal. Must throw back any game fish that is caught though. We threw a cast net about a month ago and had more than we could handle in 30 minutes. Did that first and then went bass fishing.
If I am wrong about cast netting tilapia let me know.
1984 Ranger 372V 1984 Johnson 140
1998 Fisher FX19 Tournament 1998 Mercury 200