ASTM ISO/ASTM51940-13 PDF

SIGNIFICANCE AND USE 4.1 The major use of factory-reared insects is in sterile insect release programs (for example, Sterile Insect Technique, or SIT) for suppressing or eradicating pest populations (2,3). Large numbers of reproductively sterile (irradiated) insects are released into an area where a wild “target population” of the same species exists. The wild population is reduced to the extent that the sterile males are successful in mating with wild females. The radiation dose absorbed by the factory-reared insects should be within a range that induces the desired level of sterility without substantially reducing the ability of factoryreared males to compete with wild males for mates. Species targeted by SIT programs are typically major pests affecting agriculture or human health, so the assurance by standardized dosimetry that insects have been properly irradiated is of crucial importance to agriculture growers, agricultural regulators, public health officials, and the public (3). The irradiator operator must demonstrate by means of accurate absorbed-dose measurements that all insects have received absorbed dose within the specified range. 4.2 Another use of factory-reared insects is in the production of parasitoids for release against populations of insect pests (4). Parasitoids are insects that spend the larval stage feeding within or on the body of a “host” species, typically killing the host. In some parasitoid programs, factory-reared host insects are irradiated before being offered to parasitoids. This eliminates the need to separate unparasitized hosts from parasitoids so that fertile, unparasitized host insects are not inadvertently released into the field. 4.3 Factory-reared insects may be treated with ionizing radiation, such as gamma radiation from 137Cs or 60Co sources, or X-radiation or electrons from accelerators. Gamma irradiation of insects is often carried out in small, fixed-geometry, dry-storage irradiators (5). Dosimetry methods for gamma and X-ray irradiation ... SCOPE 1.1 This guide outlines dosimetric procedures to be followed for the radiation-induced reproductive sterilization of live insects for use in pest management programs. The primary use of such insects is in the Sterile Insect Technique, where large numbers of reproductively sterile insects are released into the field to mate with and thus control pest populations of the same species. A secondary use of sterile insects is as benign hosts for rearing insect parasitoids. The procedures outlined in this guide will help ensure that insects processed with ionizing radiation from gamma, electron, or X-ray sources receive absorbed doses within a predetermined range. Information on effective dose ranges for specific applications of insect sterilization, or on methodology for determining effective dose ranges, is not within the scope of this guide. NOTE 1—Dosimetry is only one component of a total quality assurance program to ensure that irradiated insects are adequately sterilized and fully competitive or otherwise suitable for their intended purpose. 1.2 This guide provides information on dosimetry for the irradiation of insects for these types of irradiators: selfcontained dry-storage 137Cs or 60Co irradiators, self-contained low-energy X-ray irradiators (maximum processing energies from 150 to 300 keV), large-scale gamma irradiators, and electron accelerators (electron and X-ray modes). NOTE 2—Additional, detailed information on dosimetric procedures to be followed in installation qualification, operational qualification, performance qualification, and routine product processing can be found in ISO/ASTM Practices 51608 (X-ray [bremsstrahlung] facilities processing at energies over 300 keV), 51649 (electron beam facilities), 51702 (large-scale gamma facilities), and 52116 (self-contained dry-storage gamma facilities), and in Ref (1)2 (self-contained X-ray facilities). 1.3 The absorbed dose for insect sterilization is typicall...