In the museum at Preuilly there is a small object called a croix de Phylloxera, but it is quite different to the sort of wayside cross with inscription imploring God to help that comes up in searches. Since I can find out no more about it, I am restricted to telling you what the museum card says:
Croix de Phylloxera (or Verdun Necklace). They were impregnated with camphor (which was believed to be an insecticide) and placed at ground level in pairs to encircle the base of the vine. They were 'invented' by the priest at Pouligny-Saint-Pierre, who ran a factory manufacturing them from 1882 - 1898.All museums have their share of these quirky and obscure little objects. The only way of keeping their history alive is to make sure the stories are recorded while they are still within living memory. Small locally focused museums can be just as good at doing this as the great national institutions, but they are totally reliant on the community for their success. It's a credit to the local archaeological society that Preuilly's museum has some real treasures and genuinely sheds light on past times.