Indianmeal Moths

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The Indianmeal moth is among the most important and common stored product pest in the United States. Infestations of Indianmeal moths are not limited to pantries inside homes. Indianmeal moths can thrive in grocery stores, food processing plants, grain storage facilities, and other areas where food is available.

HOW DO I KNOW IF I HAVE INDIANMEAL MOTHS?

  • Indianmeal moths are easily seen.

  • While the adults are weak flier, Indianmeal moths are mobile and capable of finding suitable food resources.

  • When flying, Indianmeal moths fly in an irregular, zig-zag pattern. 

  • Adult Indianmeal moths are chiefly night flyers, becoming most active at dusk.

  • They are attracted to light, and can be attracted to TV's.

  • During the day, Indianmeal moths prefer to rest on walls, ceilings, boxes, and in poorly lighted areas.

WHAT DO INDIANMEAL MOTHS LOOK LIKE?

  • Indianmeal moth adults are about 3/8” in length with a 5/8” to ¾” wingspan.

  • The outer half of the wing is reddish-brown colored and the inner half of the wing is grayish-white colored.

  • Indianmeal moth eggs are small and grayish to dirty white in color.

  • The mature Indianmeal moth larvae are about ½” in length and dirty white, pink-brown, or light green.

  • The head and top of the first body segment behind the head are reddish brown or yellowish brown, depending on its food.

  • Indianmeal moth pupae are reddish-brown and about 3/8” in length. They are enclosed inside silken cocoons.

HOW CAN I TELL IF I HAVE INDIANMEAL MOTHS OR CLOTHES MOTHS?

  • Indianmeal moth adults are easily distinguished by the color of their wings; adult clothes moths have no rusty brown or reddish colored scales on the outer half of the wing

  • The Indianmeal moth larvae have five or six ocelli (eyespots) on each side of the head; clothes moth larvae have either one pair or none.

  • Indianmeal moths affect food products and not fabric.

ARE INDIANMEAL MOTHS DANGEROUS?

No. They do no transmit or carry pathogenic agents.

CAN MY HOUSE BE DAMAGED BY INDIANMEAL MOTHS?

  • No, Indianmeal moths do not damage the structure of your home.

  • Indianmeal moth larvae cause the most damage by consuming food and by leaving behind their feces, shed skins, silk threads, and other debris in your stored food products.

  • Although the adult Indianmeal moth do not feed, they reproduce and lay eggs on various food materials, including but are not limited to, flour, cereal grains, seeds, dried fruits, pet food, spices, ornamental products, etc.

HOW DID INDIANMEAL MOTHS GET IN MY HOUSE?

  • Indianmeal moths usually are introduced by bringing into your home already infested food products, including pet food and birdseeds.

  • Carefully examine any foods that may potentially be infested, including any type of dry pet food. If the insect is found in any of your food items, toss them out right away. There is no cost-effective way of salvaging the food without the insects.

  • Additionally, some adult moths do fly into buildings through open doors, windows, vents, etc.

WHAT DO INDIANMEAL MOTHS EAT?

  • Larvae of the Indian meal moth feed on grains, grain products, dried fruits, nuts, cereals, and a variety of processed food products.

  • In addition, Indianmeal moth larvae are capable of chewing through thin plastic bags and cardboard.

  • Indianmeal moth larvae are general surface feeders. Which means the larval feeding is confined to the surface of the stored product. However, in small, loose food packages, larvae may spread to various layers of the infested product.

  • Adult Indianmeal moths do not feed.

WHAT IS THE LIFECYCLE OF INDIANMEAL MOTHS?

  • Like other moths, the Indianmeal moth goes through a complete metamorphosis: egg, larvae, pupa, and adult.

  • Female Indianmeal moths lay between 39 - 409 eggs, with 128 being the average.

  • Eggs hatch in 2 to 17 days.

  • The optimal temperature range for development is 79 to 84°F.

  • Indianmeal moth larvae will mature in about 5 weeks.

  • While feeding, Indianmeal moth larvae produce a silk like "webbing" material throughout the infested areas and products. Food materials may be completely matted with this webbing if the infestation is heavy.

  • In order to pupate, larvae move away from the infested products and spin cocoons along ceiling and wall joints, on top of and under cabinets and shelves, in the folds of cardboard boxes or cartons, and in nearby cracks and crevices. At this time, homeowners generally start to notice the presence of the IMM problem.

  • The Indianmeal moth pupal stage lasts about two weeks.

  • The newly emerged adult Indianmeal moths mate and lay eggs about two to three days later.

  • Adults live a relatively short period of time (2-30 days) and cause no damage. They simply mate, lay eggs and die.

  • An entire life cycle can be completed within four weeks under favorable conditions.

  • There can be 4-8 generations of Indianmeal moths per year depending on the temperature, humidity, and food conditions.