The Mott insulating state of the Hubbard model at half-filling could be depicted as a spin liquid of singly occupied sites with holon-doublon quantum fluctuations localized in pairs. In one dimension the behavior is captured by a finite value of the charge parity string correlator, which fails to remain finite when generalized to higher dimensions. We recover a definition of parity brane correlator which may remain nonvanishing in presence of interchain coupling, by assigning an appropriate

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... tional phase to the parity breaking fluctuations. In case of Hubbard ladders at half-filling, we find that the charge parity brane is non-zero at any repulsive value of interaction. The spin parity brane instead becomes nonvanishing in the even-leg case, in correspondence to the onset of the spin gapped D-Mott phase, which is absent in the odd-leg case. The behavior of the parity correlators is also analyzed by means of a numerical DMRG analysis of the one- and two-leg ladder.