Effects of 67 herbicides --several of which were mixtures --and plant growth regulators on adult females of the rove beetle, Aleochara bilineata, were investigated in the laboratory. The pesticides were tested in concentrations equivalent to the highest recommended dosages for practical use. Mortality, egg production and hatch of the eggs were measured.Most herbicides had no serious effect on any of the parameters recorded. Among the urea herbicides, however, several showed adverse effects on egg production and/or hatch of the eggs laid. The strongest effect was exerted by methabenzthiazuron that impeded hatch of the eggs completely. Bromoxynil, pyridate and haloxyfop reduced survival, egg production and/or egg hatch to some degree, while carbaryl, which is also used as a plant growth regulator, killed all the beetles immediately. The usefulness of dose-response-studies and the importance of measuring sublethal effects are stressed, and the choice of herbicides showing no toxic effects is recommended.KEY-WORDS: Side-effects, pesticides, beneficial arthropods, Aleochara bilineata, herbicides, plant growth regulators, laboratory test method.The need for information about side effects of pesticides on natural enemies of pests was discussed by SamsCe-Petersen (1993). In that paper, the co-operation within the IOBC Working Group "Pesticides and Beneficial Organisms" and the joint pesticide testing programmes performed by this group were described as well. Six of these programmes have now been completed, with the latest results summarised by Hassan et al. (1994).A standardised laboratory test for the rove beetle Aleochara bilineata (Gyll.) has been developed by SamsCe-Petersen (1987). Until now, 45 insecticides, 37 fungicides and 67 herbicides/plant growth regulators have been tested. In the present paper, the method is briefly described and results of tests with 67 herbicides and plant growth regulators are presented and discussed. Some of the results have been published earlier by SamsCe-Petersen (1987), with a detailed description of the test and documentation of its reproducibility. Others were published by Hassan et al. (e.g. 1994) but only as belonging to one of four evaluation categories. The remaining results have not been published before. Some of (~) Present address: