A roller machine has been developed to help minimize cell damage during leafcutter bee larvae harvesting from polystyrene blocks. The rollers deform the block slightly to dislodge the larvae strings from the tunnel walls. The deformation used by most producers is 1/8" to 3/16" on 3" blocks and 1/8" to 1/4" on 3 3/4" blocks. Polystyrene block nesting material is fairly resilient and rebounds approximately half of the applied deformation. The vast majority of polystyrene block users pre-roll their blocks before attempting larvae removal. We recommend pre-rollering polystyrene blocks before extracting with the Dual PINMATIC Harvester.