The transition in the magnetic reconnection rate from the resistive ma
gnetohydrodynamic (MHD) regime where the Alfven wave controls reconnec
tion to a regime in which the ions become unmagnetized and the whistle
r wave mediates reconnection is explored with 2-D hybrid simulations.
In the whistler regime the electrons carry the currents while the ions
provide a neutralizing background. A simple physical picture is prese
nted illustrating the role of the whistler in driving reconnection and
the rate of whistler mediated reconnection is calculated analytically
. The development of an out-of-plane component of the magnetic field i
s an observable signature of whistler driven reconnection.