Indianmeal Moth
(Plodia interpunctella)
Adult moth: 14–20 mm
Larva: approx. 10 mm
Identification marks
The base of an adult indianmeal moth’s forewings is yellow grey and the tips are multi-coloured bright russet red. Its head is also russet red. Its antennae are long and curve forwards.
The larva is grey in colour, slightly transparent and has a brown head.
Occurrence
The indianmeal moth comes to Finland with imported goods. It is brought in with dried fruit, almonds, nuts, sweets and medicaments. The female lays eggs in the abovementioned produce. The larvae weave a white web tissue, which also includes their excrement.
A fully grown larva sometimes encapsulates a long way from its place of growth. For example, it can choose a small crack behind a cupboard or a painting for its cocoon. You can see the adult moths flying around the rooms a long time after the contaminated products have been destroyed and the storage cupboards have been cleaned.
Damage
The larvae eat nuts, grains (also flour) and dried fruits.
Prevention and extermination
Extermination in contaminated spaces is difficult, as the larvae can spread far. If a product package is seriously contaminated, it should be destroyed. It the product is only mildly contaminated, it can be frozen, which kills the moth eggs. Contaminated cupboards should be cleaned carefully.