Damage (Apple Sawfly)

• The egg-laying slit in the side of the flower soon turns brown and this is readily visible as an early sign of infestation.
• Young larvae tunnel just beneath the surface of the skin of developing fruitlets leaving characteristic ribbon scars.
• Larvae bite large cavities inside fruitlets, consuming the flesh and the seeds and producing masses of wet, brown-black frass which is exuded through a large hole in the side of the fruitlet.
• Fruitlets with ribbon scars may remain on the tree until harvest but those with more severe damage fall from the tree.
• Losses can be severe, particularly when the amount of blossom or crop set is light.