Yuck. Looks like wax moth larvae to me - more than I’d be comfortable with to leave to the bees to control. I’d recommend taking a thorough look at all the corners, crevices and grooves on frame joints, inner cover, brood box and bottom board - especially the bottom board. If you have a Flow issued bottom board or similar, there is more than one position for the coreflute to be placed - meaning there’s a vacant set of wax moth condos under there 
You can also hang a wax moth trap somewhere near/behind your hive -