Fungus Gnat and Thrips Control - Hypoaspis miles, Dalotia coriaria Rove beetle and Steinernema feltia nematodes.
Stratiolaelaps scimitus formerly Hypoaspis miles feed upon small, soil inhabiting insects, mites, and all stages of springtails. Is primary a predator of fungus gnat larvae in the soil, but it also consumes thrips pupae on the floor and soil surface of the greenhouse. It is a scavenger and can feed on soil debris in the asence of thrips pupae and fungus gnat larvae. They are a native soil mite and can adapt to a variety of different growth media and capillary mats. They are less than 1 mm (1/20 inch) in size, light brown in color, and can be seen moving quickly on the soil surface and base of plants. Hypoaspis are used primarily for control of fungus gnats, but they also help with western flower thrips control.
Dalotia coriaria is a soil dwelling rove beetle. It is an effective predator of fungus gnat larvae, shore fly eggs, pupating thrips, as well as other small, soft bodied arthropods in and around your rooting system. Dalotia are capable of flight and adapt well to various growth media including rock wool and coconut fiber. They are a generalist predator that feeds on a wide range of small insects and mites but is primarily an egg predator. It is harmless to plants and humans. Dalotia can give excellent control of fungus gnats and shoreflies. Dalotia will also prey on moth flies, root mealy bugs, springtails, cabbage root flies and carrot flies. Results have been impressive when used in conjunction with Stratiolaelaps to help prevent root aphids.
Steinernema feltia is the most effective species for managing fungus gnats. Nematodes are mixed with water and applied as a soil drench. Nematodes reproduce and search for hosts so may provide longer-term control after several applications when soil is moist, and temperatures are warm.
Stratiolaelaps scimitus (formerly Hypoaspis miles) is a soil-dwelling mite capable of the prevention, control, and management of sciarid flies, shore flies, root aphids and various thrips and soil pests.
Dalotia (Atheta) is a soil dwelling rove beetle. It is an effective predator of fungus gnat larvae, root aphids, shore fly eggs, pupating thrips, as well as other small, soft bodied arthropods in and around your rooting system. They are a generalist predator that feeds on a wide range of small insects and mites but is primarily an egg predator. It is harmless to plants and humans. Dalotia can give excellent control of fungus gnats and shoreflies. Dalotia will also prey on moth flies, root mealy bugs, springtails, cabbage root flies and carrot flies. Results have been impressive when used in conjunction with Stratiolaelaps to help prevent root aphids.
Steinernema Carpocapsae nematodes (SC) is most effective against flea larvae, ticks, ants, and caterpillars in lawns, garden soil, and under trees where larvae pupate. S. carpocapsae tends to be most effective when applied against highly mobile surface-adapted insects. Steinernema carpocapsae nematodes use sit-and-wait strategy ambush to attack highly mobile insects.
Steinernema feltiae nematodes are the product of choice when your problems concern more active, shallowly occurring pests of fungus gnat or mushroom fly larvae, root aphids, etc. These nematodes feature a shallowly-present habit like S. carpocapsae, but an intermediate active-hunting “cruising” characteristic which may make them superior to many other species for the purposes specified. In fact, due to their shallow-cruising nature, S. feltiae are said to be the best nematodes for fungus gnat larvae and root aphids They tolerate cold better than the others as well.
Populations of Hypoaspis include both sexes, but the males are much smaller and rarely seen. Under a hand lens most stages of this mite look similar. Hypoaspis inhabit the top few centimeters (inch) of soil only. Eggs hatch in about 2-3 days, and the life cycle is completed in about 11 days. These predatory mites feeds upon the young larvae of fungus gnats in the soil, and are most effective when applied to soil before fungus gnat populations are establised. Hypoaspis consume 1-5 prey per day and can survive as a scavenger by feeding on algae and plant degris. Hypoaspis tolerate a variety of conditions except flooding. They can survive mild winters but are inactive below 57 degrees F.
Hypoaspis are for preventative control only, before fungus gnat populations are high. They are supplied in a peat mixture in one liter containters and should be aplied as soon as they are recieved, but can be held at room temperature for limited periods if absolutely necessary. Introduce 1-2 litres per acre for greenhouse vegetables and 1 liter per 1000 square feet for bedding plants.
Rove beetle is most effective when applications are started before fungus gnat population becomes well established or while numbers are still low. Because rove beetle has a longer life cycle and takes longer to establish than the Stratiolaelaps predatory mite, so should be used along with Stratiolaelaps for best results.
Release throughout the greenhouse at a rate of 100- 1,000 per greenhouse weekly or biweekly, depending on greenhouse history of shore flies and fungus gnats. To ensure reproduction and mating, release 50-100 in one spot in the center of the release area. Be sure to treat areas with wet, exposed areas of soil where fungus gnats and shore flies are likely to breed.
Steinernema feltiae, an insect parasitic nematode, has been used extensively for fungus gnat control for many years. S. feltiae is a microscopic, non-segmented roundworm that seeks out and enters fungus gnat larvae through natural body openings like the mouth or anus. S. feltiae uses carbon dioxide, movement and vibrations to locate larvae. Once inside, the nematodes release symbiotic bacteria that quickly kill targeted insects. Reproduction inside the insect releases new generations of infective juvenile nematodes that disperse in search of further prey. Applications of nematodes should be made to moist soil and applied in the early morning or late evening to avoid high temperatures, UV exposure and nematode desiccation.