Effect of pesticide mixtures on the predatory mite Phytoseiulus persimilisAH (Acarina, Phytoseiidae) in the laboratory

The acaricide hexythiazox (Acorit(R) SC, 100 g a.i.l(-1)), the fungicide tr iadimefon (Bayleton spezial(R) WG, 52 g a.i.kg(-1)) and the insecticide hep tenophos (Hostaquick(R) EC: 550 g a.i.l(-1)), were tested in the laboratory for their side-effects on the predatory mite Phytoseiulus persimilis A.H. The pesticides were either applied separately at a range of concentrations or in admixture to detached bean leaves using a Potter Tower to deposit 2 m g spray solution per cm(2) No significant differences in the mean mortality rate of the phytoseiid or in the mean reproduction per female was found be tween the different treatments. Total effect values ranged from 5.4 to 38.7 % after separate application of the test products and from 8.9 to 25.5% aft er treatment with the various pesticide mixtures.