Ecotoxicological laboratory test for assessing the effects of chemicals on terrestrial isopods.

Several laboratory methods for studying sublethal effects of chemicals on organisms have been developed in recent years. One of the aims of such tests is to identify whether use in the field will result in unacceptable ecological damage to non-target species. Most tests have been developed for single species, but at present, very few are required by law before a product can be released onto the market. Indeed for terrestrial ecosystems, the only test that is widely-used is the earthworm toxicity test (Greig-Smith et al. 1992). The range of species for which test procedures are being developed is expanding. For example, several authors have recommended methodologies for tests with terrestrial isopods (Eijsackers 1991; Van Straalen 1993; Van Straalen and Verweij 1991; Van Straalen and Van Gestel 1993; Van Wensem et al. 1992). Criteria measured in these studies include growth, reproduction and survival in response to toxicants. However, terrestrial isopods have a long reproductive cycle and can survive for up to 180 days without food (Donker 1992). Thus, there is a need to develop a test which examines a parameter that has ecological relevance, but which can be measured in a relatively short time.