In the past, I've used Di-Syston as a granular application to keep
pests from bothering shrubs and trees. However, I see that it is no
longer available.

I've got a tree with something that keeps "stinging" the branch tips,
laying eggs, and then borers or something seem to be eating the tree.
It is actually a peach tree, but there won't be any fruit on it until at
least next year, so it wouldn't be an issue using something systemic at
this point.

Can anyone recommend a granular systemic insecticide to use as a
replacement? I couldn't find anything at all like that when I browsed
the fair sized garden chemical section at Lowe's this morning.

Thanks!