Aderyn Pest Control

Stored Product Insects

These are pests that can be detected feeding and harbouring in food. Stored product insects are any insect which infest stored food, whether in the raw material state or processed. They can be divided into three forms:

  • Beetles
  • Moths
  • Mites

Within these three forms there are many families of different stored product insects, or SPI as we call them. For example, meal moths, rice weevils, cheese mites, and larder beetles. Ultimately, they all feed on grain or animal products. Tobacco, fat, and animal hides are also susceptible sources of food.

Where to Find Them

SPI are found anywhere where they can gain access to a stationary food supply of grains and animal products. Fast-flowing systems such as pneumatic spouting in mills do not usually support insect infestation, as there is no anchorage for harbourage. Food materials resting inside pantries, and dead spaces in food processing machinery is generally where infestations will be found.

Temperature and favourable conditions are a factor determining where SPIs will congregate. Typically, most stored product insects prefer warm and damp conditions that don't exceed 25 degrees Celsius. For example, no infestation will withstand the heat of a bakery oven.

Machinery handling certain parts of the production of foods is more susceptible to insect infestation than others. Different parts of manufacturing systems may have their own pest problems. 

Reasons to Control Stored Product Insects

Prevention of Damage - Larvae with spun silk threads can cause blockage in machinery and damage to working parts. Food materials and insect remains can also get trapped and form a hard mass. Millions of pounds and delays in production can be lost through insect infestations causing damage. Contact our pest control in Cardiff to keep your property pest-free. 

Prevention of Loss - Insects eat large amounts of food when developing from larvae to adults. Infestations can cause a considerable loss of product that you have paid for. Grain can also germinate from heat and moisture produced during insect growth. Infested grain can also heat up and produces 'hot-spots' reaching more grain, which becomes unusable.

Prevention of Contamination - Insects of certain species, for example mites and flour beetles, produce taint. Bacteria can also grow. Contaminated products therefore quickly become unfit for consumption and sale. This is important to control for exported products, as certain countries have stricter limits of permissible insect particle contaminants.

Prevention of Production delays - Infestations cause stoppages, often resulting in costly loss of production time.

Prevention of Loss of Reputation - Consumers finding insects in your products may result in loss of business, goodwill and reputation, know when it's time to call in a commercial exterminator.

Prevention of Cross-Infestation - Infested raw materials and food brought into factories, can cause cross-infestation onto clean food and manufacturing equipment.

Look for the following signs.

  • Dead or alive insects in food storage areas
  • Moth webbing or frass (excreta)
  • Damaged and eaten food products
  • Smell taint given off from infestation by beetles or mites
  • Tracks or footprints in flour or grain
  • Insect fragments
  • Flying SPI moths
  • Buff-coloured mite dust
  • Insects flushed out with pytrethroid aerosol




Stored Product Insects, Pest Conrol Cardiff, Bridgend