whoa! NEVER seen anything like that...bet it took some guts just to take the picture. bee suit, wet bed sheet, rope. throw the wet sheet over the mess, tie it off, if it takes it....if the mess calms down, stop it off, add a screen to allow air. but wonder what caused the weekness to began with.
usually the first signs of robbing looks like a drunk being thrown out of a bar. a couple of hive bees dragging a bee or two out. the robber goes for a tumble and flies off. the guard bees will be aggravated, darting toward every bee that tries to enter. the robbers (they are carring no load) will fly in high and try to land inside the hive instead of landing on the board and walking in. sometimes they will fly in and withdraw several times before trying to land (although this is easily confused with new hive bees taking their first flight). the successful robbers will (in early stages of robbing) climb up the face of the hive (they are heavy with honey) and then take flight.
seems like alot of things in my life. if you ask yourself "does that look like robbing?" IT IS. stop down the hive or screen it off altogether before its too late. better to combine a weak hive to another one than loose it altgether.