The invention relates to novel compounds of the formula (I)in which R1, R2, R3, R4, R5, R6, Y1 and Y2 have the meanings given above,to a plurality of processes and intermediates for their preparation and to their use as acaricides and/or insecticides for controlling animal pests. The compounds of the formula (I) are also suitable as nematicides for plant-damaging pests and/or anthelminthics for endoparasites in humans and animals.