谷物和豆类 隐蔽害虫侵染的测定 第4部分：快速方法（ISO 6639-4:2025）

1.1 This document specifies four rapid methods for estimating the degree of, or detecting the presence of, hidden insect infestation with sampling (see Clauses 4 to 6) or without sampling (on-site probing, see Clause 7) in a cereal or pulse lot. NOTE The characteristics leading to the choice of rapid method are summarized in ISO 6639-1:2025, Table 1. 1.2 The method by determination of carbon dioxide production (see Clause 4) is applicable to testing whole grains. It does not apply to testing: a) finely ground grain products, as there is a risk that particles of material will be sucked up with air samples; or b) grain products with moisture contents greater than a mass fraction of 15 %, because of the risk of carbon dioxide produced by the products themselves and by microorganisms interfering with the results. In addition, the method does not apply to the rapid testing of grain products onto which carbon dioxide has already been adsorbed in large quantities (e.g. grain stored in a confined atmosphere, when there are clear external indications of heavy infestation). The method is applicable to coarsely milled or kibbled grain products, provided that they have been sieved before testing to remove fine particles and loose insects. The method does not permit the presence of dead adults. 1.3 The whole grain flotation method (see Clause 5) is applicable to detecting hidden infestation in most cereals and pulses but only on a qualitative basis. 1.4 The acoustic method operating on a grain sample (see Clause 6) is applicable to detecting living (and active) insects (larvae and adults before their emergence from a kernel) inside grains in a sample. It does not permit dead adults and larvae or living eggs and pupae (non-feeding stages) to be detected. 1.5 The on-site assessment acoustic method (see Clause 7) is applicable to detecting adult insects and larvae feeding on the grain inside without taking samples. It does not apply to detecting inactive stages (eggs, nymph and moulting).