Stored Product Insects - Beetles, Moths & Mites

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 stored product insects, or SPI as we call them

Reasons to control SPI

• Prevention of Damage
  Insects eat large amounts of food in developing from eggs to adults. Infestations in food materials can course a considerable loss of weight in the product.
  
  Larvae with spin silk threads. e.g. moth can cause blockage in machinery and damage to working parts, as food materials get trapped in the sliks and form a hard mass. Millions of pounds of food value is lost through insect infestation.
• Prevention of Loss
  Example
  Infested grain can be downgraded to animal feed, hides can be damaged by beetle larvae holes and may be rendered valueless. Grain can germinate from heat and moisture produced during insect growth. Bacteria can also grow. Grain heats up and produces 'hot-spots' of heavily infested grain, which is then unsusable.
  
  Tobacco can be ruined by tobacco beetle damage. Insects of certain species, e.g. mites and flour beetles, produce taint.
• Prevention of Contamination
  Contaminated foodstuffs are usually returned. Certain countries do not allow importation of foodstuffs containing more than set limits of insect particle contaminants.
• Prevention of Loss of Production
  Insect which block equipment or infest machinery cause stoppages, which result in costly boss of production time.
• Prevention of Loss of Goodwill
  Food contaminated by insects result in loss of business, goodwill and reputation. Insects in food also cause distress.
• Prevention of Cross-Infestation
  Infested raw materials and good brought into factories can cause cross-infestation onto clean food and manufacturing equipment.

Detection of Stored Product Pests

What to look for:

• Dead or live insects
• Moth webbing or frass (excreta)
• Damaged good e.g. holes, moths/grain weevils leave grain as hollow shells.
• Smell - taint given off from infestation by beetles or mites.
• Tracks - these fall into three categories:
  • Beetles - double row of footprints
  • Larvae - solid line where body of larva has dragged along.
  • Moth - footprints plus wing marks.
• Insect fragments
• Flying moths
• Buff-coloured mite dust
• Insects flushed out with pytrethroid aerosol

Stored Product Insect Pests can either be detected feeding and harbouring in food trapped in the fabric of a premises or within spillage in dead spaces insice machinery iteslf.

Machinery handling certain parts of the production of foods is more susceptible to insect infestation than others. e.g. no infestation will withstand the heat of a bakery oven. Different parts of manufacturing systems may have their own pest problems. Fast-flowing systems such as pneumatic spouting in mills do not usually support insect infestation as there is no anchorage for harbourage. Where food materials rest inside equipment is generally where infestation will be found.

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