Mediterranean Flour Moths
Order: Lepidoptera
Family: Pyralidae
Scientific Name: Anagasta kuehniella
The Mediterranean flour moth,
a stored-product pest, was introduced into the United States around 1900.
The adults cause no damage.
However, the larvae infest products such as flour, cereal, beans,
biscuits, dog food, dried fruits, nuts, seeds, and a wide variety of other
commodities.
Description
The adult moth has a wingspread about 1 inch. The wings are a pale gray with two black zigzag transverse stripes. At rest the adult moth has a characteristic pose: the front of the body is raised causing the wings to have a downward slope with the tip of the abdomen protruding upward between them. The mature larva is pinkish-white and approximately 5/8 to ¾ inch long. The head and prothoracic shield (area just behind the head) are dark brown to black. The lateral aspect of each abdominal segment has a hardened ring around the seta, giving the appearance of dots down the side.
Biology and Habits
The female can lay several hundred eggs in food material. The eggs hatch within several days. The larvae, which live in silken cocoons, mature in about 40 days. In addition to contaminating and consuming food products, the larvae cause significant damage as they crawl around spinning silken threads. This activity mats food particles together which subsequently can clog machinery and require shutdown for cleaning.
Pupation occurs in clean
food or in cracks and crevices.
The complete life cycle (egg to egg-laying adult) usually requires
8 to 10 weeks; however, at warmer temperatures it may be as short as 4
weeks.
Control
In residences, locate the infested material and destroy it, or disinfest it by placing it in a freezer for five to seven days, or in an oven at 60 degrees C (140 degrees F) for 30 minutes. Because the larvae tend to seek protected areas for pupation, a crack-and-crevice treatment may be necessary. PCOs can use space sprays to control adults.
In commercial accounts prevention is the first step in an effective control program. Prevention methods include thorough inspections of incoming products, proper rotation of materials prone to infestation, and sanitation, particularly the clean-up of spilled products.
Light and pheromone traps
are effective surveillance tools and provide limited control.
A careful inspection will determine whether crack-and-crevice treatments
and space sprays are necessary.
Infested products can be fumigated.
(Courtesy of the National Pest Control Association.)