The direct treatment of seeds (cereals and legumes) during transfer to the storage cell or during transilage, with contact insecticides (which leave persistent residues on the grains) is increasingly being called into question and is prohibited in seeds for organic farming.
Corrective solutions to eradicate hidden forms of weevils in cereals or bruchids in legumes involve the use of gases:
- Phosphine gas fumigation, which must be carried out in sealed or temporarily sealed cells for the duration of the fumigation, is most often carried out by a specialized company with the administrative authorizations required to handle toxic gases in closed environments. It is most often used in large "flat" stocks under tarpaulin or in dedicated cells, well sealed against toxic gas and fitted with an external piping system allowing "recirculation" of the gas to shorten the immobilization time of the goods (Ciesla, 2018) ;
- Disinsectisation by exposure to inert gases is suitable for eradicating bruchids from batches of legumes that arrive bruised at harvest;
- Insects can also be destroyed by heat: simply reach a core temperature of 55°C and all stages of insects in stored grain die within minutes. However, as the investment is very high, these processes should be reserved for products with very high added value (e.g. cereal-based foods for therapeutic diets, baby-food or laboratory animal feeds). However, seeds or malting barley can be seriously damaged by heat treatment.