Includes one package of each of the beneficial nematodes that ARBICO Organics supplies: Heterorhabditis bacteriaphora, Steinernema feltiae and Steinernema carpocapsae. Use this combination to achieve the broadest coverage of a wide variety of soil dwelling pest populations or if you are unsure of the specific pests you have. Beneficial nematodes are live microscopic organisms (non-segmented round worms) that occur naturally in soil throughout the world. They are parasitic to insect pests that typically have a developing (larval or pupal) stage of life in the soil. They have been known to parasitize above ground stages of adults, nymphs and larvae. They will not harm mammals, aquatic life, birds, reptiles or amphibians.