Causes of infestations

Insect pests in stored grain need certain living conditions to feed, reproduce and survive. In some cases you may have unwittingly provided an ideal living environment for insects even before grain is stored. The following measures are effective and simple ways of preventing pest development:

  • Thoroughly cleaning the inside of the bin
  • Removing spills or grain lying outside of bins
  • Cleaning and treating structures before filling them. This is especially important prior to harvest.

Grain is a biological organism that deteriorates. Maintaining your grain bins will protect grain and help maintain its optimum quality. Weatherproofing grain bins helps keep out insects. It also seals grain bins from moisture that can lead to spoiling and a reduction in grain quality.

Weed management around bins is as important as controlling weeds in the field. Weeds or volunteer cereal grains around bins, as in this photo, attract insect pests. Various weed seeds discovered in a grain shipment can result in a prohibition of export. Keeping areas around grain bins clean helps prevent insect infestations in stored grain.

A photo shows the outside of a grain bin
Weeds growing near a grain bin; long grass, weeds, and spilled grain have not been removed

Insect pests in stored grain are considered either primary or secondary.

  • Primary insect pests have the ability to infest, feed and reproduce on whole, sound grain.
  • Secondary insect pests require mould or damaged grain kernels to survive. Secondary insect pests indicate the following:
    • The presence of mould and that grain is going out of condition. Grain that is mouldy may appear whole.
      or
    • That primary insect pests have infested and damaged the grain.

Many stored product insect pests are strong fliers. They can migrate distances that are greater than just a few metres. When grain is warm, it emits odors that attract insect pests from great distances. When stored grain is properly maintained, there is less chance of mould growth and insect infestations and subsequent damage to grain quality.