Preparation of a test guideline – Hypoaspis reproduction test – in particular for the assessment of plant protection products

The aim of this project, which was supported by the German Environment Agency (UBA), was to standardise and validate a test guideline using soil predatory mites, a Hypoaspis reproduction test. Testing effects of plant protection products on predatory soil mites may be needed for the listing of an active substance in Annex I of EU Directive 91/414/EEC (EC 1991), which regulates the authorisation of plant protection products in the European Union. Predatory mites are considered important biological indicators to assess potential effects of plant protection products. They are widespread in various habitats, play a prominent role in the arthropod community, and represent an additional trophic level to the species, for which guidelines are already available. A standardised draft guideline was developed by an ad-hoc international working group, consisting of twelve laboratories representing industry, agencies, universities and contract laboratories coming from three European countries. The group performed 48 test runs, two for each test chemical (the insecticide dimethoate and the industrial chemical boric acid). In addition, each test was run twice, following either an ECx or a NOEC design. The results of the ring test showed that the proposed test method is practical, sensitive and robust enough to be proposed as a new standard test guideline. It was adopted by OECD in 2008.