Insect pests like parasitic nematodes species are actually beneficial! Steinernema carpocapsae are best suited to cooler climates, and are most effective against mobile pests such as termites, fleas, fungus gnats, webworms, and sod webworms. Heterorhabditis bacteriophora are adapted to all climates, and are most effective against sedentary pests, such as grubs, root weevils, and black vine weevil. For the best treatment of ants, termites and general soil-borne pests, a combination of nematodes is recommended. Available in sprayers, pump sprayers or motorized sprayers, and solutions over the ground that may require continuous mixing.

These nematodes attack the larval stages of soil-dwelling pests, while leaving the plants alone to control the soil. The parasitic nematodes work by entering their prey and releasing bacteria that kills their host within 48 hours. The nematodes can then use the dead host as a nest, and reproduce within. (Take note, Horror movie directors!)

Nematodes are recommended for use whenever pest larvae or grubs are present, generally during the spring and fall months. If adult insects are present, their eggs will be hatching soon. As a treatment for Japanese Beetles, parasitic nematodes take effect more quickly than Milky Spore, but keep in mind, more than one application may be necessary.