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Larva BioControl for Manure and Litter Fly Larvae

Larva BioControl contains the entomopathogenic nematode Steinernema carpocapsae and is currently sold with crop and garden directions. Use in manure, litter and stable bedding against fly and beetle larvae requires a label amendment and state acceptance and is in development.

The target: larvae in manure and litter

House flies and stable flies breed in moist manure, spilled feed and soiled bedding, and a generation can complete in about a week in warm weather. Adult sprays reach only the flying fraction of the population, and resistance to pyrethroids and other adulticides is widespread in house flies. Litter beetles in poultry houses follow a similar pattern, with larvae in litter and pupation in walls and insulation. Hitting the immature stages in the substrate is the lever most programs underuse.

How the nematode works

Infective juveniles of S. carpocapsae enter insect larvae through natural openings and release the symbiotic bacterium Xenorhabdus nematophila, which multiplies and kills the host, typically within 48 hours. The nematodes reproduce inside the cadaver and release new infective juveniles. S. carpocapsae is an ambush forager that waits near the substrate surface, which suits larvae moving through the upper layer of manure and litter. Performance depends on moisture, temperature and ammonia levels in the substrate.

Status and practical limits

Macroscopic biological control agents such as nematodes are exempt from EPA pesticide registration, but product directions and state rules still govern use. Our premise directions for manure and litter are in development, with trials measuring larval suppression under farm conditions. Nematodes are live and must be stored cool and applied within their shelf life. They are not compatible with fresh application of chlorine dioxide or other disinfectants on the same substrate.

Key facts

Steinernema nematodes carry Xenorhabdus bacteria and Heterorhabditis carry Photorhabdus; the bacteria kill the insect host (Kaya and Gaugler 1993, Annu Rev Entomol 38:181)
S. carpocapsae is an ambush forager that remains near the substrate surface (Lewis et al. 2006, Biol Control 38:66)
Biological control agents other than microorganisms, such as nematodes, are exempt from FIFRA registration (40 CFR 152.20(a)(1))
House flies breed in manure, spilled feed and wet litter in poultry and livestock facilities (Axtell and Arends 1990, Annu Rev Entomol 35:101)

How our delivery technology applies

Nematodes are live organisms, so this product does not use the nano-encapsulation platform. The delivery challenge is survival: infective juveniles need moisture and protection from ultraviolet light and ammonia. Our development work focuses on carrier and timing (application to moist substrate after cleanout, before larval peaks) rather than encapsulation.

Join the manure and litter trial for Larva BioControl.