生態毒性試験のためのセスジユスリカの飼育方法

抄録

In Japan, several aquatic organisms such as fish, daphnia, and monocellular algae have been used for assessing the environmental impact of agrochemicals. Recently, Daphnia magna, which is a representative species of arthropods (crustaceans and insects), was confirmed to be less susceptible to some insecticides than many other crustaceans and insects. Therefore, it is of concern that the environmental risk of several pesticides would be underestimated using the present evaluation system, and it is considered that additional species are needed for more accurate risk assessment. In this context, midges (Chironomus sp.) are attracting attention as a suitable species for such testing. Use of Chironomus sp. for testing has been recommended in the OECD Test Guideline No.235 (TG235). However, there are some technical issues involved in the use of Chironomus sp. according to TG235 for toxicity testing; the most important is the issue of how healthy larvae can be consistently collected through the year for the test. We have established a breeding and cultivating methods for Chironomus yoshimatsui on a small-scale and a cheap apparatus with self-made readily available materials in our laboratory. Our methods can provide a constant subculture for the acute toxicity test