  This paper considers a semilinear integro-differential equation of Volterra
type which interpolates semilinear heat and wave equations. Global existence of
solutions is showed in spaces of Besov type based in Morrey spaces, namely
Besov-Morrey spaces. Our initial data is larger than the previous works and our
results provide a maximal existence class for semilinear interpolated heat-wave
equation. Some symmetries, self-similarity and asymptotic behavior of solutions
are also investigated in the framework of Besov-Morrey spaces.
