Rabbit droppings and grasshoppers were collected on recently graded coal mine spoil to determine if they were vectors of endomycorrhizal fingi. After 6 weeks of growth, roots of rye grass and sudan grass grown in mixtures of sterilized sand containing either unsterilized rabbit droppings or grasshoppers were endomycorrhizal, while the roots of plants grown in sterilized mixtures of those were not.
Ponder, Felix Jr. 1980. Rabbits and Grasshoppers: Vectors of Endomycorrhizal Fungi on New Coal Mine Spoil. Research Note NC-250. St. Paul, MN: U.S. Dept. of Agriculture, Forest Service, North Central Forest Experiment Station