  Given Banach spaces $\X$ and $\Y$ and Banach space operators $A\in L(\X)$ and
$B\in L(\Y)$, let $\rho\colon L(\Y,\X)\to L(\Y,\X)$ denote the generalized
derivation defined by $A$ and $B$, i.e., $\rho (U)=AU-UB$ ($U\in L(\Y,\X)$).
The main objective of this article is to study Weyl and Browder type theorems
for $\rho\in L(L(\Y,\X))$. To this end, however, first the isolated points of
the spectrum and the Drazin spectrum of $\rho\in L(L(\Y,\X))$ need to be
characterized. In addition, it will be also proved that if $A$ and $B$ are
polaroid (respectively isoloid), then $\rho$ is polaroid (respectively
isoloid).
