The present invention relates to novel compounds of the formula (I), in which W, X, Y, Z, G, A and t have the meanings given above, to a plurality of processes and intermediates for their preparation and to their use as pesticides and/or herbicides. Moreover, the invention relates to selective herbicidal compositions comprising, firstly, the spiroheterocyclic tetronic acid derivates and, secondly, a crop plant compatibility-improving compound. The present invention furthermore relates to increasing the activity of crop protection compositions comprising in particular phenyl-substituted bicyclooctane-1,3-dione derivates by adding ammonium salts or phosphonium salts and, if appropriate, penetrants, to the corresponding compositions, to processes for their preparation and to their use in crop protection as insecticides and/or acaricides and/or for preventing unwanted plant growth.
