Date of this Version
Scouting, prevention and control of the iris borer.
This insect is the most serious insect pest of iris in Nebraska and is found virtually everywhere in the state. Damage is characterized by dark, streaked, or watery areas and ragged edges on the developing leaves of iris in May and June and extensive destruction of the insides of the rhizomes in July and early August. Examination late in summer will reveal a large white to pinkish caterpillar from 1 1/2 to 2 inches long in the rhizome, usually accompanied by a foul-smelling soft rot.