Just keep in mind that a percentage of the toxin to kill them will get into the plant, then into you if eaten, some will get into the groundwater, and some will get into creatures eating the grubs. Some of it will continue to toxify the soil for variable periods of time.
Whatever you use, do so sparingly.
I've had corm-borers attach my FHIA 23. I grow cultivars that resist corm borers and nematodes.
