  Building on work of Zhi-Hong Sun, we establish congruences for the special
harmonic numbers $H_\lfloor p/9 \rfloor$ and $H_{\lfloor p/18 \rfloor}$ modulo
$p$, which contain respectively three and four distinct arithmetic components.
We also obtain a complete determination modulo $p$ of the corresponding
families of sums of reciprocals of the type studied by Dilcher and Skula.
Applications to the first case of Fermat's Last Theorem are considered.
