A previously developed electron cascade model is extended and used to examine the laser wavelength-dependence on the threshold intensity in laser-induced electrical breakdown of molecular gases. The analysis is based on numerical solution of the time-dependent Boltzmann equation and a set of rate equations describing the population of the involved excited states. The calculations are restricted to molecular hydrogen at atmospheric pressure irradiated with tunable laser radiation ( lambda =720-800 nm) with a pulse duration (FWHM) of 18 ns. The computed threshold intensities are compared with those experimentally measured. The calculated electron energy distribution function and its parameters provide an important correlation between the laser wavelength and the relevant physical processes involved during the interaction.

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