Integrated pest management resources for Michigan Michigan State University home IPM Michigan home
IPM Scouting in Herbaceous Perennials

Search
Resources
bulletChristmas trees
bulletField crops
bulletFruit
bulletHome and yard
bulletNursery and landscape
bulletTurfgrass
bulletVegetable

Related pest diagnostic/management programs
Diagnostic Services ● Soil/Plant Nutrient Lab ● Enviro-weather ●Regional IPM Center ● Pesticide safety ● Organic: New Ag Network ● Invasive species ●Sustainable ag & food systems

Organizations
MSU ANR departments ● MSU Extension ● Site index ●Contacts/permissions
Iris borer
IPM scouting in herbaceous perennials > iris borer
Iris borer larvae initially feed at the tops of plants, chewing holes in leaves and giving leaves a ragged appearance. They eventually create dark-streaked areas that appear watery. Larvae migrate down the plant, and then mature larvae bore into leaves a few inches above the growing medium surface. Mature larvae then feed within the rhizome, creating large tunnels. The tunneling causes plants to wilt severely and eventually rot. The adult iris borer is a nocturnal moth with dark purple front wings and yellow-brown hind wings. Females lay eggs in plant debris. Iris borer overwinters in the egg stage.

Management: Remove debris from adjacent areas. Clip and remove dead iris leaves and stems to eliminate any overwintering eggs. Contact insecticides need to be applied before the larvae enter leaves. Frequent applications may be necessary in the spring.
Iris borer damage
Iris borer damage.
Iris borer larva Iris borer damage
The mature larvae of iris borer are 2 to 5 cm long, fleshy, smooth and pink with black spots on the side. Iris borer damage.
This information was developed from A Pocket Guide for IPM Scouting in Herbaceous Perennials by Jan Byrne and Raymond A. Cloyd. Purchase this in a pocket-sized guide for reference in the orchard from MSU Extension (publication E-2981).
The MSU IPM Program maintains this site as an access point to pest management information at MSU. The IPM Program is administered within the Department of Entomology, fueled by research from the Michigan Agricultural Experiment Station, delivered to citizens through MSU Extension, and proud to be a part of Project GREEEN.
Email the web developer.
Updated 9/28/07