6639/1 (TSO nternational Standard Cereals and pulses - Determination of hidden insect infestation Part 1 : General principles First edition - 1986-12-01 UDC 633.1 : 635.65 : 632.7 Ref. No. 1SO 6639/1-1986 (E) iO6639/1-1986 Descriptors: agricultural products, cereal products, leguminous grains, tests, determination, insects, contamination, generalities. Price based on 2 pages Copyright International Organization for Standardization ted without license from IHS Not for Resale Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (isO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with iso, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by ieast 75 % approval by the member bodies voting. International Standard ISO 6639/1 was prepared by Technical Committee ISO/TC 34, Agricuituralfoodproducts Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its latest edition, unless otherwise stated. International Organization for Standardization, 1986 . Printed in Switzerland Not for Resale itted without license from IHS INTERNATIONAL STANDARD ISO 6639/1-1986 (E) Cereals and pulses -- Determination of hidden insect infestation Part 1 : General principles Introduction species also take advantage of holes or cracks in grains to enter and feed inside them. These insects constitute a hidden infes- This International Standard describes methods of determining tation that cannot readily be seen in consignments or samples. hidden insect infestation in cereals and pulses. It consists of the Most insect pests of stored grains are very small, under 5 mm following parts : in length, cryptic in behaviour and dull in colour. Those that fly do so mostly in dull light or at high temperatures. Thus, even Part1:Generalprinciples. when they are living freely outside the grains and do not con- Part 2: Sampling. stitute a hidden infestation as described above, they are not easy to detect unless populations are large enough to induce Part 3: Reference method. noticeable activity. Part 4: Rapid methods. Being mobile, at least in the free-living form, insects are capable of moving through a bulk of grain and tend to concen- Scope and field of application trate in those parts of the bulk most favourable for feeding and breeding. Such centres of insect activity are not necessarily This part of ISO 6639 establishes the general principles of static; they may expand, contract or move for many complex The most important reasons are changes in the methods of determining hidden insect infestation in cereals and reasons. physical condition of the grain (for example temperature and pulses. moisture content) and overcrowding of the insects due to rapid breeding. Thus, the distribution of insects in a bulk of grain is rarely random, and their detection requires specialist knowi. 2 Definitions edge and techniques. For the purpose of Iso 6639, the following definitions apply. Sampling 2.1 initial observed infestation: Those free-living insects that are immediately apparent to the eye when the sample is The methods of sampling cereals and pulses specified in first examined. ISO 950 1) and ISO 9512) are not appropriate for sampling for hidden infestation in cereals and pulses, because of the non- 2.2 hidden infestation: Those insects which are present random distribution of insect populations, particularly after a within individual grains either because they are at juvenile period of.prolonged storage or transportation. stages and have developed from eg