  Energy momentum tensor of a quantized massless bulk spin-$\frac{1}{2}$ field
in five dimensional warped cosmological spacetimes is studied. The four
dimensional part of our model represents a warped cosmological thick brane and
the scale of the extra dimension is time-dependent. We use a simple ansatz to
solve the Dirac equation in the bulk that helps us to compare our results with
the known four dimensional case. Renormalisation of the components of the
energy momentum tensor is achieved using adiabatic regularization method. We
compute the leading order finite contribution to the stress-energy tensor which
is of adiabatic order six. The resulting energy and pressure densities
explicitly show the effects of the so-called warping factor and the dynamic
extra dimension on the created matter. We show how the energy density produced
are localized to form 3-branes along the extra dimension.
