And if grain storage space was desperately needed business assessments dictated the cheapest corrugated metal silo available. This type of silo is common in most parts of the world even though it does not prevent condensation and subsequent moulds or the immigration of insects and is not easily cleaned because of grains getting stuck between metal sheets and not easily sealed for fumigation. But with good weather conditions and sufficient wind, storage in corrugated metal silos may still cause few problems. Only if hot and moist weather conditions occur together with high numbers of flying grain pest insects could major losses occur. Locally, these losses may be higher if a given grain storage remains largely unattended. In Europe, most larger grain storages have thermometer cables to survey the development of a hot spot caused by insect respiration and mould development. Studies are under way to find out if acoustic or optic devices could provide an even better early warning measure at feasible costs.

What is integrated stored product protection?

One can distinguish between preventive methods, monitoring methods to detect pest organisms and control methods (see Figure).