Objective of the study

Preliminary range finding tests, or preliminary screening tests, are generally conducted to assess the biological activity and host range of the pesticide (if relevant), as well as to provide an indication of effective dose rates.

The results of these tests provide complementary information to the field efficacy trials, in particular as a basis to justify minimum effective dose rates or to extrapolate between pest species or crops.

Circumstances in which the study is required

Preliminary range finding or screening tests are generally not a standard requirement of the application for registration. However, they may be requested by the registrar, in particular if minimum effective dose tests in the field are not available, or when extrapolating between pest species or crops.

Test conditions

Preliminary range finding or screening tests are often conducted in the laboratory or under semi-field conditions.

Test substance

Preliminary range finding or screening tests are generally conducted with a formulated product, though not necessarily the one for which registration is sought.

Testing guidelines

Many guidelines and protocols exist for laboratory and semi-field testing on the efficacy of pesticides. However, few international or regional guidance is avialable. They include:

• The WHO Pesticide Evaluation Scheme provides protocols for laboratory and semi-field testing of insecticides against vectors of human disease. Available at: https://extranet.who.int/pqweb/vector-control-products/who-efficacy-testing-guidelines-vector-control-products
• The European and Mediterranean Plant Protection Organization (EPPO) publishes a few guidelines on laboratory testing (e.g. stored products pests, rodents) as part of their Standards for efficacy evaluation of plant protection products. Available at: http://pp1.eppo.int
• OECD provides various guidelines for laboratory testing of antibacterial and antimicrobial products, disinfectants, and certain household pests. Available at: http://www.oecd.org/chemicalsafety/testing/seriesontestingandassessmentotheregpesticideresiduechemistry.htm
• ASTM International provides various guidelines for laboratory testing of (mainly household and public health) pesticides and antimicrobials. Available at: https://www.astm.org/products-services/standards-and-publications.html