  For a particular class of Stratonovich SDE problems, here denoted as single
integrand SDEs, we prove that by applying a deterministic Runge-Kutta method of
order $p_d$ we obtain methods converging in the mean-square and weak sense with
order $\lfloor p_d/2\rfloor$. The reason is that the B-series of the exact
solution and numerical approximation are, due to the single integrand and the
usual rules of calculus holding for Stratonovich integration, similar to the
ODE case. The only difference is that integration with respect to time is
replaced by integration with respect to the measure induced by the single
integrand SDE.
