feltiae

Feltiae refers to Steinernema feltiae, a species of entomopathogenic nematodes in the family Steinernematidae. These microscopic roundworms are obligate parasites of insect larvae living in soil and are widely used as a biological control agent in agriculture and horticulture. Steinernema feltiae maintains a mutualistic relationship with bacteria of the genus Xenorhabdus, which are carried in the nematode’s gut and released into the insect host to help kill it.

The infection process begins when infective juveniles locate a susceptible insect larva in the soil. The nematodes enter through natural openings or wounds, release their bacterial symbionts into the host, and cause septicemia. The bacteria rapidly multiply, killing the host within 24 to 48 hours. Nematodes feed on the decaying tissue and the bacteria, reproduce within the cadaver, and emerging juvenile nematodes migrate to seek new hosts.

Host range is broad for soil-dwelling larvae, including fungus gnats, beetle and moth larvae, and other pest insects. Because of its effectiveness against fungus gnat larvae in greenhouse settings, S. feltiae is one of the most commonly used EPNs in integrated pest management programs. Applications are typically in the form of aqueous suspensions, drenches, or granules, delivered through irrigation systems or targeted sprays.

Environmental considerations include the need for adequate soil moisture and moderate temperatures, typically around 12–25°C. Nematodes are sensitive to UV light and desiccation, and shelf life varies by formulation; they are generally stored refrigerated before use. S. feltiae is regarded as safe for humans and other non-targets when used as directed.