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In the middle of the blister, on its lower surface, is a small opening, which permits the gall mites (phytoptus pyris) to pass out of the blister. The cells in the middle of the leaf are torn apart.

Blister Formed by Phytoptus Pyris by Leaf

In the middle of the blister, on its lower surface, is a small opening, which permits the gall mites…

Pictured are pear leaves attacked by phytoptus pyris, also known as gall mites. A represents a leaf recently attacked by mites. B represents a leaf with old mite galls.

Pear Leaf Attacked by Phytoptus Pyris

Pictured are pear leaves attacked by phytoptus pyris, also known as gall mites. A represents a leaf…