Same

Have never found a real solution. Once the larva are in there its.almost impossible to get them out without killing the plant. Best ive managed to do is keep them alive long enough to make a single harvest. What i do is wrap foil around the base when they’re very young. Stops young larva from being able to burrow in. Also mound & bury the runners and (wrap the protuding bits) like potatos when they get big so there is multiple root nodes when the original dies.