Mediterranean Flour Moth

Although not of worldwide distribution, this pest owes its common name to the belief that it originated in the Mediterranean region; others believe a Central American origin. It was first found in the United States in 1892, in California.

Recognition

Adults have a wingspread of about one inch or less. Front wings are pale gray, each with two black zigzag transverse lines. Hind wings are dirty white. This moth has a distinctive resting pose in which front of body is raised giving wings a distinct downward slope with tip of abdomen protruding up between them.

Mature larva are about 5/8-3/4 inch long, pinkish white in color, head and prothoracic plate/shield dark reddish brown, and with some darker areas about base of some seta but no rows of spots on dorsum or backside. With five pairs of well-developed prolegs on abdomen, each bearing crochets. Perspiracular tubercle of prothorax with two setae. Tubercle VI on mesothorax with one sta. On most of body, pinacula present. With larger dark thickened ring about base of seta III of mesothorax and abdominal segment eight. Spiracle of eighth abdominal segment about diameter of pale area enclosed by dark thickened ring about base of seta III.

Habits

The adults cause no damage. The larvae cause most of the problems, because as they crawl around extensively, they spin silken threads which mat food particles together. These silken food mats clog flour mill machinery, sometimes causing shutdown until they are removed. In homes, this extensive crawling about means the larvae can be found anywhere.

Adults are attracted to light.