Beneficial nematodes, or parasitic and predatory nematode worms, are environmentally friendly natural parasites of insects pests but do not harm plants or other animals. They are an effective, non-chemical control method of many soil-dwelling insect pests. Introducing nematodes into your garden controls pests without the use of pesticides for natural pest control in the garden.
Steinernema feltiae are entomopathogenic, or insecticidal, nematodes that are effective against larvae of various immature (larvae) dipterous insects such as Sciarid flies, fungus gnats, tipulids, and mushroom flies.
Nematodes are part of the roundworm family, and are very commonly found in moist soils. You may already have this type of nematode living in your garden, but in lower levels than a nematode treatment would contain. These nematodes are called “beneficial” or entomopathogenic and are completely harmless to humans, animals, and non-target pests. They live in the soil, and have a complicated life cycle. The “dauer” third larval stage is the infective stage, and the nematodes will enter their host through any body opening they can find or even through the insects exoskeleton. The nematodes release bacteria that kill the insect in a few days. The nematodes actually eat the bacteria, and the bacteria are attacking the host; the bacteria are the primary agents responsible for killing the insect host.
When you apply nematodes to your yard or garden, you will introduce a very high number of these nematodes to the system. Eventually, if the treatment works successfully, all or almost all of the target insects will die, eliminating the hosts for the nematodes and the high populations of nematodes will also be diminished.
Nematode Pest Control
Beneficial nematodes are used for many soil dwelling pests, including white grubs (from Japanese beetle, oriental beetle, chafer beetle, and June beetle larvae), cutworms, sod webworms, pillbugs, many borers, and some caterpillars. Doing research on the pest you want to get rid of will help you to determine if you can use nematodes in your pest control regimen.
How to Use Beneficial Nematodes
Since nematodes are living organisms, transporting and storing them can be difficult and delicate. There are several things you need to know when using this type of pest control. As with any do-it-yourself pest control project, always read the label for instructions, warnings, and safety precautions.
You can buy beneficial nematodes from garden centers and online distributors. They have a very short shelf lives.
Use nematodes very soon after you get them. They need to be kept cool and in a dark place, like a refrigerator, to keep them dormant.
Often, nematodes will come in a foam block or clay pellets. Dissolve in barely warm water (right above room temperature). These animals can be spread in a watering can or with a sprayer with a large enough nozzle.
Heat and sun (UV light) causes these creatures to quickly deteriorate and die. Don’t apply nematodes during times of direct sun.
Soil temperature should not be too cool; for the type of nematode we sell (S. Feltiae) 58 degrees to 68 degrees will create a good soil environment.
Soil needs to be moist. Water before and after application, and for several days afterwards to ensure the environment is right for the nematodes to do their work.
Clean up debris before applying; excess weeds, rocks, and leaves can make it difficult for nematodes to get to the soil.
You will probably not physically see insects dying, but do not think your control measure isn’t working. If the damage from the pest insects continues to get worse over a week or two, you might have to reapply nematodes.
Nematodes are sometimes advertised to work for fleas. The type of nematode you purchase will determine the flea control you will experience. The type S. carpocapsae has been studied and found to be effective against fleas.