The more we learn about lawn and garden pests, the more we’ve come to love beneficial nematodes. Part of this comes from our study of various grub and worm pests that spend some of their lives in the soil. The other comes from the enthusiastic stories we’ve heard about the value of these microscopic pest destroyers.
The stories offer curious examples of the trial-and-error ways we come to learn about the gardening craft. And it’s also about the value of an Integrated Pest Management program, one that uses a variety of practices to deal with pests at all stages of development, not just when we start noticing damage to our lawns or our fruits and vegetables.
Some of these stories start with yellowing turf or with scattered dead spots in a lawn. Good organic gardeners don’t wait for such problems to fester. These people had treated their lawns with insecticidal soaps. Some sprayed Bt-k, the naturally occurring soil bacteria. Their targets were white grubs, sod worms, mole crickets, webworms. These treatments are good for knocking down pests at a particular stage at a particular time. One story said that repeated BTK applications over a rainy week yielded results (BTK works best when applied in dry conditions) but then damage started to reappear. He’d only taken care of one stage of the pests. While he was destroying worms, pupae waited in the ground.
In a moist, dark environment Beneficial Nematodes kill almost all pests. Therefore, they are ideally suited to combat insects in and on the soil and those that bore into wood, trees and shrubs. Each pint contains 10 million active units and treats 285-550 square feet, or 1,050 4-inch pots. Instructions for care and release are provided with each order.
It wasn’t until the next spring that he applied beneficial nematodes. These wormy little microscopic parasites move through the earth until they find something to eat. They occur naturally in good rich soil that hasn’t been treated with chemical pesticides. Non-beneficial nematodes are vegetarians. They chew on roots and plant matter in the soil. Beneficial nematodes are carnivores. They don’t feed on plants. They feed on the pests that attack plants.
They can be an effective treatment, either concentrated on an infested area or broadcast in sufficient amounts over an entire lawn. The more pests they consume, the greater their numbers. They’ll consume any grubs of any kind they encounter. Knowing your target pest’s lifecycle can increase the effectiveness of nematode application. If you’re seeing Japanese beetles in your lawn, you know that other generations are there as well. Waiting three or four weeks and reapplying will help eliminate remaining pupae .
We’ve been told that we should wait until the soil begins to warm in the spring before broadcasting the critters. The thinking is that cold ground would not be encouraging. But it’s also suggested that late season is a good time to apply them to a lawn that’s had trouble, as we’ve learned. As long as the ground isn’t frozen or doesn’t freeze while the nematodes are seeking out prey, they’ll be fine. They actually prefer damp soil, so cold wet spring weather shouldn’t be a deterrence to use them. Fall applications might be best after cleanup and before applying compost if you so choose. As the lawn takes to its hibernation, the nematodes will be finishing off any pupae hiding underground, one by one.
In the meantime, those insect parasitic nematodes will also be going after other vermin who seek shelter underground: flea beetles, thrips, cucumber beetles, cutworms, even fleas. Beneficial nematodes don’t harm earthworms. They’re tunneling lubrication is too thick and slimy for the little nemi-worms to penetrate. But a thin-skinned pupae? (They’re also used extensively indoors and in greenhouses to control fungus gnats.)
Parasitic nematodes can be part of a good pest management program when used in an effective way. Any time you can eliminate two of a pests three stages, you’ve got them on the ropes.
Eric Vinje founded Planet Natural with his father Wayne in 1991, originally running it as a grasshopper bait mail-order business out of a garage.
Eric is now retired, but is still a renowned gardener known for his expertise in composting, organic gardening and pest control, utilizing pesticide-free options, such as beneficial insects.
Eric believes when you do something good for the environment, the effects will benefit generations to come.
13 Responses to “Worm-Like Parasite Attacks Insect Pests”
I have an infestation of Springtails as a result of a yard that has accumulated years of leaf rot and covered in ivy. Of a house I bought 6 months ago. I have since cleaned up yard (removing rotting leaves, vines etc.) and spread Biden granules around property. They have moved into my home as well. I have been treating them indoors in numerous ways but have yet to completely get rid of them. I’ve had them identified by Entomologist and have confirmed they are indeed springtails. I have an intense allergy to them and they are incredibly irritating to my skin. Do you have any suggestions. Everyone I talk to and everything I read seems to have contradictory info and opinions. I have also tried to use a pest control company to no avail. I have researched and read more than I ever wanted to know about this pest but have yet to have success. I found info on your website regarding using other live insects and nematodes to rid of pests. Is there anything that has been found to feast on springtails? I would greatly appreciate any info you could share to help me with this overwhelming terrible problem. By the way this all started when I began cleaning and clearing our yard in March of 2016. As you can imagine, I am ready to get these pests out of my life or at Leary reduced to where we can all live in harmony together.:)
Thanks for your time. I look forward to hearing from you.
Have you seen our page on springtail control?
Hope it helps!
How long should I wait after using diatomaceous earth on the garden before applying the beneficial nematodes? Our garden is full of wireworms and cut worms .. hoping these nematodes will help. I apply diatomaceous earth last evening and in my area we are expecting 50-100ml of rain this weekend.
Hi Toni –
Diatomaceous Earth and Scanmask Nematodes are compatible. There is no need to wait before applying.
I have fungus gnats and have been watering with hydrogen peroxide. This is not working. So I have just ordered Nematodes from you. Will the peroxide already in the soil kill the Nematodes ?
Hi Beverly –
If you have already stopped watering with hydrogen peroxide you should be good to go with beneficial nematode applications. I would also suggest using yellow sticky traps placed horizontally to catch the adult gnats.
I have a fungus gnat infestation in my tropical terrarium, are an effective way to get rid of them without harming my beneficial springtails? I haven’t seen any since the gnats started taking hold inside the terrarium, I’m also wondering if the gnats killed my springtails…
Meant to ask if nematodes an effective way to get rid of gnats but not springtails.
Moved into a house with FLEAS!!! Previous family had pets obviously they never treated the poor pets. Commercial exterminators were an absolute JOKE!!! Expensive!!! And not at all knowledgeable.
One company said they didn’t even treat for fleas. Another tech came out and said they “didn’t see any” although I had caught a BUNCH and put them in a large mason jar with water and there was RED BLOODY water at the bottom of the jar. Also had peeled back off of contact paper and caught a BUNCH that way on the sticky side. Showed him ALL these and he STILL said he didn’t see fleas. Checked his company with BBB and found numerous complaints. ANYWAY won’t be calling anymore exterminators!!!
I have a cat staying with a friend. SO can beneficial nematodes be used indoors in a house? Like Neem Attack Triple Threat? Are they safe for humans? Are they safe for cats? Would want to bring my cat in at the earliest possible time. He is about a year old and he is treated for fleas and ticks on a monthly basis by his vet.
Thanks. And are the beneficial nematodes safe for neighborhood cats and dogs that comen in the yard? There are several here. Thanks again.
Will nematodes work on Apple Maggots? I live in Colorado Springs… should I apply in fall or spring?
Hi Kelli –
Beneficial nematodes are microscopic, worm-like parasites that actively hunt, penetrate and destroy the pupal stage of apple maggots. For best results, apply in the early spring or fall around the base of trees, out to the drip line. One application will continue working for 18 months.
Learn safe, natural and organic solutions to get rid of apple maggots here https://www.planetnatural.com/pest-problem-solver/tree-pests/apple-maggot-control/.
Hope it helps!
Will nematode treatments around my pecan trees in our yard be safe for my kids to play around?
I have fungus gnats in my houseplants. If the beneficial nematodes kill off the larvae, what happens to the nematodes when there are no more creatures to eat?