Guideline for the evaluation of side-effects of pesticides. Encarsia formosa

This guideline is concerned with the evaluation of the side-effects of pesticides on Encarsia formosa (ENCAFO) in the glasshouse. Encarsia formosa is used for biological or integrated control of greenhouse whitefly ( Trialeurodes vaporariorum (TRIAVA)). Because field-testing is laborious and costly, this guideline includes a sequential testing scheme involving three laboratory tests, which may serve to classify many pesticides as definitely harmless or harmful without having recourse to field tests. In particular, the very stringent residual contact test on adults (the most sensitive stage) allows products to be classed as definitely harmless, since experience has shown that no product so classed by this test is ever harmful in field tests. The direct contact test on pupae (the most insensitive stage) makes it possible to exclude as definitely harmful products which have ≥ 50% effect. Products which are not harmful to pupae in this test could still kill adults after emergence if they are sufficiently persistent. So a 3-day persistence test makes it possible to exclude further products as too persistent. Finally, only products which appeared potentially harmful in the first test, but were harmless to pupae and non-persistent, have to be field tested, by comparison with harmful and harmless reference products, to decide on the final rating.