Indianmeal Moth

Introduction

The Indianmeal moth was given its common name by an early American entomologist who found it feeding on cornmeal. It probably the most important and most commonly encountered pest of stored products found in the home and in grocery stores in the United States. Of Old World origin, it is now found worldwide.

Recognition

Adults have a wingspread of about 5/8-3/4 inch. Wings are pale gray but the front wing's outer two-thirds are reddish brown with a coppery luster.

Mature larva are usually about 1/2 inch long, usually a dirty white, but color may vary to a greenish or pinkish or brownish hue depending on its food, with head and porthoracic pate/shield yellowish brown to reddish brown. This moth has five pairs of well-developed prolegs on abdomen and each bearing hooks. Prespiracular tubercle of prothorax with two setae. Tubercle VI on mesothorax with 1 seta. Body without pinacula on mesothorax, metothorax, and first abdominal segments. Rim around spiracles of about even thickness.

Habits

The adults cause no damage. The larvae are surface feeders and generally produce a lot of webbing throughout the infested part of materials. They are general feeders and attack grain and grain products, a wide variety of dried fruits, seeds, nuts, graham crackers, powdered milk, biscuits, chocolate, candies, dried red peppers, dry dog food, and bird seed. They are very destructive wherever dried fruits are stored. Preferred are the coarser grades of flour such as whole wheat, graham flour, and cornmeal, but they can breed in shelled or ear corn.