There were more larvae of the raspberry cane midge in primocanes of the red raspberry cultivar, Malling Jewel, damaged by the fish plates on a mechanical harvester than in primocanes from hand-picked rows.
There was little difference in the number of larvae occupying natural sites at the base of primocanes in hand-picked and machine-picked rows, but populations on primocanes in machine-picked rows were increased by larvae developing in fish plate wounds.