Jeff Hahn, University of Minnesota
Mary Lou Marchand
Size: Up to 2 inches long
Where/When: Tunnels inside iris leaves, eventually moving down into the rhizome. Active from April through early August.
Significance: Damage to the rhizome is often considerable, although the iris is not immediately killed. Feeding damage can allow the entry of a bacterial soft rot. Rhizomes infected by soft rot are slimy, soft and foul-smelling and can kill iris.