Does Diatomaceous Earth Kill Beneficial Insects?

Last Updated on February 28, 2022 by Grow with Bovees

Let’s talk about using DE — aka diatomaceous earth — as a way to control pests and kill insects in your garden.

Has this product been recommended to you, but you’re not sure what it is, how to use it and whether it’s ok to be used in gardens to control a pest issue or if other preventative measures are better?

Then this article is for you, as we here shall try and clarify any misunderstandings you might have about diatomaceous earth and beneficial insects.

DE is a great organic material that can be used in your garden to organically control unwanted critters roaming about. But, is it effective for all pests?

Does it also eradicate beneficial insects or other animals, crucial for a healthy garden? How to use it and are there any limitations regarding safety?

Continue on for more info about this product.

What Is DE — Diatomaceous Earth?

DE, after being extracted from sedimentary rock where it’s naturally found, comes in the form of a white, very fine, almost chalk-like substance.

This silky smooth white dust is basically ancient phytoplankton called diatoms.

To give you a better idea, diatomaceous earth derives from the fossilized remains of diatoms. Diatoms are aquatic — algae-like — single-celled microorganisms. These diatoms consist of extremely hard tiny shells which are made up of a substance called silica.

Fun Fact

Silica is among the hardest materials in the world and forms about 59 percent of our earth’s crust and 95% of all known rocks have silica as their main constituent.

Diatomaceous earth is mined and then used as an organic insecticide, in pharmaceuticals, food, cosmetics and swimming pool filters and pool maintenance.

Much like other insecticides found on the market, this one is also available in different strengths and concentrations.

Food-grade DE is considered to be the most safe and gentle form to use, making it great to use as an organic insecticide in outdoor and indoor gardens.

One can also purchase a stronger concentration of diatomaceous earth. This would be filter or industrial grade DE. It has a higher level of silica and is, considered to be poisonous to mammals.

How Does It Work on Pests and Insects?

Diatomaceous earth dust may feel silky and smooth between our fingers, but if you have a closer look at it — from underneath the microscope, for example — you will see that each individual particle has razor-sharp edges resembling broken glass.

So, if this powder comes into contact with certain targeted pests or insects, its glass-like shards would leave them with fatal lacerations and abrasions all over their body (exoskeleton), quickly damaging their protective outer layer, causing them to dry out and die.

This brings me to the question at hand, is DE safe for beneficial soil bugs?

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The answer to this question is, unfortunately, not.

Diatomaceous earth will harm beneficial insects as much as it will harm the damaging ones. This product cannot detect the difference between harmful pests and insects that are needed and are part of a healthy soil composition.

Let’s continue by discussing the benefits of diatomaceous earth and its safety limitations.

Advantageous Qualities of Diatomaceous Earth

Assuming that you are making use of food-grade diatomaceous earth, it’s safe to use around areas that are frequently used by people as it’s non toxic. These areas include surfaces such as around the kitchen sink.

The DE dust is not easily swept up by breezes or air movement, so people passing by won’t disperse the product if it’s scattered around an affected area.

If this product is inserted into cracks in walls or floor boards, keep it dry, and it may stay intact and in place for years to follow. Even small splashes of water will not break the barrier of diatomaceous earth powder.

It’s generally safe for pets and consumption of the pet-grade product should not have an effect on their health status. To be on the safe side, however, we advise that you always read the package label for precautions regarding how much of the product can safely be consumed.

Safety Limitations of Food Grade DE

Getting this product into your eyes and airways is not a good idea and people that have been diagnosed with a respiratory illness should stay away from DE all together.

When applying diatomaceous earth — or any fine dust — it is always a good idea to wear some protective gear in order to prevent irritation of the skin, eyes and airways. Important protective gear includes gloves, goggles and a face mask.

If you accidentally inhale this product, or it comes into your eyes, and you are worried, contact your doctor for further advice.

How To Apply Food Grade Diatomaceous Earth

Food grade de can be applied to many areas around the house. These include the garden, your pets and largely in and around your house — depending on where the problem is. It is quite versatile in the sense that there are a few different ways in which to apply this product. Choose whichever method works best for you.

DE works best when applying it dry. When it is dry, it is able to quickly dehydrate and kill unwanted bugs and absorb unwanted odors and spills. Sometimes, however, depending on the situation, wet application is necessary, the product starts to work once it has dried out.

As mentioned above, diatomaceous earth products come in a powdered form, which can be quite messy if applied wrongly or without the proper measuring tools or applicators.

Continue on to learn about the different methods and the proper way to apply this organic insecticide without having to hose down the entire powdery mess afterwards.

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Dry Application of Diatomaceous Earth

Using a flour sifter is a great apparatus to distribute DE indoors. It is easy, and the mess is minimal as the sprinkling is targeted at the area of your choice.

A flour sifter is great to use when you only need a light treatment, dealing with unwanted insects on carpets or rugs, for example.

Other areas in the house that could be sprinkled with diatomaceous earth using a flour sifter include underneath stoves and refrigerators, around the basements and garage, in cabinets, on window sills, in garbage cans and around baseboards. You can also use DE on pet beds and in a chicken coop, should you keep chickens.

If you want a tool that is more fancy than a flour sifter or something that is specifically designed for use when wanting to distribute diatomaceous earth, you can easily find specialty applicators on online gardening sites.

Wet Application of Diatomaceous Earth

Sometimes you will find tough spots that are hard to simply sprinkle with DE dust, as this fine substance just keeps on falling off the surface. This could be in areas such as the undersides or the top parts of your pest-infested plants.

In this case, a wet application is perfect and once the DE dust dries, it will work just as well as a dry application of DE would.

Simply mix four tablespoons of diatomaceous earth with one gallon of water. Once thoroughly mixed, pour it into a spray bottle and apply a thick layer of the mixture to the affected area and let it work its magic.

The wet mixture of diatomaceous earth can also be used as a cleaning product to clean around your home.

Other Ways To Apply Diatomaceous Earth

  • Salt and pepper shakers

Spice shakers are very convenient to use if you want to sprinkle DE on small areas or spaces.

  • A turkey baster

If you have places indoors which are in need of some diatomaceous earth powder but are hard to reach, such as corners and cracks in floor boards and walls, a turkey baster always comes in handy.

  • Nylons and mesh bags

If you have the need to deodorize DE indoors. Applying it through meshy bags works wonders.

  • Paintbrushes

If you need to apply DE to small areas with some precision, paintbrushes are easy and great to use.

Harmful Insect Pests

As mentioned above, diatomaceous earth can be used as an organic pesticide to get rid of many species of harmful and unwanted pest insects as well as to control slugs and other soft bodied insects in your home and garden.

Continue on to a list of pests that will be negatively affected if you use DE:

Bad Bugs

  • Mice — DE is able to get rid of animals such as mice as well as rats.
  • Mites — use DE and eradicate several types of mites that are often found among garden plants. Spider mites are one of the most common types of mites that are damaging the plants and ecosystem of your garden. If you find them on your plants, sprinkle DE on and around the affected area.
  • Tomato worms — these worms are a nuisance in the garden, as they feed on the freshly grown produce. Sprinkling DE on these worms will dry them out and kill them.
  • Carpenter ants — these ants are able to damage furniture. Carpenter ants especially like to make their way through outdoor or patio furniture. Sprinkling some diatomaceous earth on the colonies of carpenter ants will definitely help you get rid of them. Another great killer of ants is making a mixture of boric acid, water and sugar.
  • Horn worms —unfortunately this pest is known to infest quite a few plants, but using DE is thankfully quite effective. Spray diatomaceous earth directly onto them, and it will easily penetrate their exoskeleton and dry them out when they come in contact with it.
  • Spiders and Tarantulas— it has been shown that the DE also works when you want to kill spiders in your garden. It’s also able to break through the exoskeleton of spiders and kill them.
  • Cockroaches — mixing food grade diatomaceous earth with a bit of flour and sprinkling it around targeted areas will kill roaches. They will also see it as food and carry it to other roaches, killing them too.
  • Harmful nematodes
  • Bed bugs
  • Fungus gnats — if you find gnats flying around your house, have a look in your plants soil and find their eggs. Lightly sprinkle the affected area with diatomaceous earth.
  • External parasites
  • Internal parasites
  • Aphids
  • Caterpillars
  • Fleas
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Beneficial Insects

The downside to diatomaceous earth is that it may also kill other insects that are found in and around your garden, so we advise that you use diatomaceous earth with caution at all times. The last thing you want is to eradicate the good insects.

Here’s a list of other creatures that are negatively impacted by diatomaceous earth, avoid applying DE on these:

Good Bugs

  • Lizards
  • Earthworms
  • Butterflies
  • Pollinators
  • Beneficial nematodes
  • Praying mantis
  • Butterflies
  • Bees
  • Ladybugs

The earthworm can’t be killed by diatomaceous earth. It has a slimy layer around its body which protects it from the porous powder. Earthworms can also eat DE. It simply gets excreted again together with the castings.


With the information above, we can conclude that diatomaceous earth is a great product to use in and around your garden. But, always be careful when you use DE on plants, as DE can also kill the beneficial insects that inhabit your garden.

With this, we wish you a pest free garden. Good luck!