Indianmeal moth
Plodia interpunctella (Hübner)

Classification

Secondary pest: Grain feeder
Order: Lepidoptera
Family: Pyralidae
Acronym: PIN

Description

  • Adults have a wingspan of 14 to 20 mm and the body is 6 to 7 mm in length.
  • Forewings are bicoloured with the base (part closest to body) cream to yellow and the outer portion coppery red to dark grey.
  • Larvae are whitish though may have a greenish or pinkish tint depending on the larval food source.
  • Larvae may be distinguished from Ephestia larvae by the lack of dark spots at the base of the setae (hairs).
  • Larvae reach a length of 8 to 10 mm.

Similar species

Commodities affected

  • Cereal products, oilseeds, cocoa, chocolate, spices, nuts, dried fruit, dried roots, herbs, tobacco, some pulses, dead insects
  • Processed, packaged, manufactured foods, confectionary products

Signs of infestation

  • Webbing of food surface
  • Presence of frass (excrement), cast skins, pupal cases and dead adult moths

Damage

  • Damage is caused only by larvae and is not distinctive.
  • Only broken kernels of grain and grain dust are attacked as larvae cannot penetrate undamaged grain.
  • Infested foodstuff is covered with silky webbing and frass from larvae.
  • Webbing may clog machinery.

How to control

Geographic range

  • Is found worldwide
  • Is found coast to coast in Canada

Where found

  • Is found in granaries, stores, elevators, warehouses
  • May be encountered in manufacturing, distribution, retail and domestic environments

Life history

  • Females lay eggs directly on the commodity, eggs are sticky.
  • Pupation occurs in a silken cocoon on the surface of the food or nearby.
  • Larvae can overwinter in unheated buildings.
  • Life cycle will continue year round in heated buildings.

Images

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Did you know?

The Indianmeal moth can take anywhere from 2 weeks to 2 years to reach maturity.

Video of the Indianmeal moth

Transcript

Adult and larval Indian meal moths move across wheat kernels. The larvae move slowly while the adults crawl quickly.