Description
Beneficial nematodes are remarkably lethal to many insect pests (entomopathogenic) yet safe for plants, animals, and people. No special safety equipment or restrictions are necessary with this natural and organic pest control. Nematodes work quickly and kill insect pests within 1-2 days. They target the root-zone stage of a variety of pests, such as grubs, weevils, fungus gnats and thrips.
Nematode Mixing Instructions
Water is the carrier for nematode applications. Use the solution as a spray or as a dip for plug trays. For small scale gardeners, create a nematode solution in a bucket and water onto the crops by hand or with spray equipment. For large scale growers add nematodes to irrigation systems, backpack sprayers, tank sprayers or use a Dosatron. Remove filters less than .5mm and do not exceed 200 psi on the spray pump. Repeated applications are often needed.
Small Scale Gardeners
- Mix a stock solution. Add 3 gallons of clean room temperature water (59 to 68°F) to a five-gallon bucket and add nematodes (on sponge or in tray). Allow five minutes to disperse, mixing gently.
- If using the sponge product, very gently squeeze the sponge to release all the nematodes into the solution.
- Continue to stir throughout the application as they will sink to the bottom.
- Add 1 cup of stock solution to a 2-gallon watering bucket. Water plants to saturate the soil 2” deep. This will fill 32 buckets. Apply approximately 3oz/4” pot and 8oz /1g pot
- If you have a small area to water, do not dilute stock solution, but water it directly onto plants.
- If applying to a lawn, use a hose-end sprayer.
Large Scale Growers
- Before applying nematodes ensure that soil is moist.
- Fill spray tank or bucket for stock solution with half of the required amount of cool, clean water.
- Start agitation and add the required number of nematode trays or sponges.
- Continue agitation while mixing and fill spray tank to the required spray volume.
- Lightly spray the nematodes onto the surface of the soil.
- Maintain agitation during application to ensure uniform dispersion of nematodes.
Applying on Foliage
- Use as little water volume as possible to cover the leaf surfaces.
- Add a wetting agent.
- Apply early morning or evening or on an overcast day.
- Keep humidity high and lightly mist plants with water half an hour after application to give nematodes more time to find a host.
Instructions and Rates
Nematode Sponges
Use 1 million nematodes per 1000 ft2. This brand (Sierra) has a completely unique application rate as they are raised in vivo and the bacterial level is much higher than other products. Sponges are pre-inoculated with infective juveniles in quantities of 1 mil, 6 mil and 24 mil. Reapply in 2 to 4 weeks under moderate to heavy infestations.
Nematodes in bags/trays
These contain 50 million or 250 million. Release every 2-3 weeks at a rate of 50 mil/1100 ft2 or every 4-6 weeks at a rate of 50 mil/550 ft2. Use 30-50 gal/1000ft2.
Target Pests
Different nematode species will target specific pests. Often nematodes are used for fungus gnats, shorefly, cutworm, weevils, leafminers, western flower thrip, grubs, fleas, armyworms, webworms, and more.
Life Cycle
A complete life cycle takes 12-15 days at room temperature. Soil temperatures should be above 50°F but avoid applying when the soil temperatures are above 80°F. Optimum soil temperatures are between 60-70°F for most species. Use a soil thermometer to monitor temperature if needed.
The nematodes enter the insect pest through body openings. Once inside they reproduce and release a symbiotic bacterium which is toxic to the host. The pests are killed within a few days and a second generation of infective juvenile nematodes exit the host and begin the cycle again.
Quality Control and Viability
Always check nematode viability before application if there has been a delay in shipment or a temperature compromise. Use a black background and a 10x magnification hand lens or field microscope to observe the nematodes. Once at room temperature, place a small amount of the product in a small clear container or Petri dish. Add 1 to 2 drops of room temperature water. Wait a few minutes and look for actively moving nematodes which will be curvy or 'S' shaped. Cold or dead nematodes will be straight like a pin and not moving. See video below.
Use in Biological Control
Entomopathogenic nematodes are supplied as infective juveniles, which are usually applied as a soil drench. Not all nematodes are alike. They specialize in which pests they attack and kill and are effective at different temperatures. The common pests listed below are just a sampling of what these nematodes will attack.
- Steinernema kraussei (Sk) can work in the lowest temperatures of all available nematodes, 40-86°F, and targets black vine weevil larvae.
- Steinernema feltiae (Sf), targets fungus gnat larvae and western flower thrips pupae, as well as other insects in the Diptera order. They work in cooler weather and can survive and infect in temperatures between 50-88°F.
- Steinernema riobrave (Sr) is active between 59-95°F. It targets turf and citrus pests like weevils, cutworms and grubs. Heat tolerant and adapted to warm soils.
- Heterorhabditis bacteriophora (Hb), targets beetle grubs, lepidopterous and coleopterous insect larvae, root and black vine weevils. Works best in soil temperatures between 61-95°F.
- Steinernema carpocapsae (Sc), targets shoreflies, billbugs, cutworms, webworms, armyworms, wood-borers and other lepidopterous larvae. Works best between 68-88°F. Sc is an ‘ambush’ forager, standing on its tail in an upright position near the soil surface and attaching to passing hosts, even capable of jumping.
- Greenhouse Blend targets fungus gnats, shore flies and western flower thrips pupae. Contains a mix of Steinernema carpocapsae and Steinernema feltiae. S. carpocapsae is relatively sedentary and tends to remain near the soil surface to 'ambush' its hosts, whereas S. feltiae will search more actively through the substrate.
- Lawn and Garden Blend targets fleas, crane fly, grubs and weevils. Contains a mix of Steinernema carpocapsae and Heterorhabditis bacteriophora.
- 3-Way Blend is best for broad coverage and contains Steinernema carpocapsae , Steinernema feltiae and Heterorhabditis bacteriophora.
For Best Results
- Use fresh nematodes. Examine under a microscope and look for wiggly live worms. Dead ones are straight as a pin.
- Nematodes can be stored in the refrigerator for 2-3 weeks.
- Apply early in the morning, in the evenings or on a cloudy day as nematodes are susceptible to desiccation and UV light.
- Apply to already moist soil and keep the soil moist for several days after the application. Soil should be 54-86 °F. Avoid overwatering so nematodes aren’t washed out of the containers.
- Remove all filters that are 50 mesh or finer if using sprayer and keep pressure below 300psi.
- Once mixed, use within a few hours or they could die from lack of Oxygen. Keep solution agitated or add a bubbler, as nematodes will sink to the bottom.
- Do not mix nematodes with fertilizers but it’s okay to apply them directly before or after a fertilizer.
- Volume of water used depends on size of the container and the depth the target pest is in the substrate.
- Nematodes can be combined with the predatory mite Stratiolaelaps scimitus for complete control.
- Treat as soon as possible (2 to 3 days) after sticking cuttings, planting plugs, or starting seeds.
- Repeated applications are often needed. Reapply in 2 to 4 weeks under moderate to heavy infestations. For longer term crops, apply at the beginning and at mid-crop.
- Nematodes are compatible with several different pesticides; however, they are generally not compatible with organophosphates, carbamates, nematicides, and hydrogen dioxide.