  Brane inflation predicts the production of cosmic superstrings with tension
10^{-12}<G\mu<10^{-7}. Superstring theory predicts also the existence of a
dilaton with a mass that is at most of the order of the gravitino mass. We show
that the emission of dilatons imposes severe constraints on the allowed
evolution of a cosmic superstring network. In particular, the detection of
gravitational wave burst from cosmic superstrings by LIGO is only possible if
the typical length of string loops is much smaller than usually assumed.
