How does diatomaceous (DE) earth work?

An insect that has been treated with diatomaceous earth.

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Diatomaceous earth is a mechanical pesticide that sticks to any insect or mite that crawls through it. The shards of DE scratch the protective coating and get stuck in all the joints as well as coating the sensory organs. This leaves the pest vulnerable to drying out and unable to find its way around.

What is diatomaceous earth?

Diatomaceous earth is a fine, off white coloured powder, made from the fossilised remains of microscopic aquatic organisms called diatoms. The skeletons of these tiny creatures is made of a natural substance called silica.

Diatomaceous earth is made of amorphous silicon dioxide that has been milled to a superfine powder.

Below: I tested 5 brands of diatomaceous earth on over a million insects and mites. You can see how the diatomaceous earth has covered the antennae and clogged the joints.

This video is shot at 6X magnification  to show the details. You can see in the video that the insect is trying to clean itself and as it does the DE will damage the mouth parts.

Diatomaceous earth is not a poison and other than needing to kept completely dry it requires no special storage conditions.

How does diatomaceous earth work?

Diatomaceous earth is a mechanical pesticide that works by clogging and damaging the limb and body joints and waxy cuticle or coating on insects and parasites and by interfering with their ability to breathe. It also clogs the antennae and eyes blocking the insects ability to sense its environment.

Diatomaceous earth desiccates the fleas, mites and worms and it does that by scratching them to death whilst it is completely non-toxic to the treated animal.

Below: You can see how the DE has collected in the joints of these worms, rendering some of them almost immobile just a few minutes after treatment.

When used internally in the intestines of chickens it scratches away at the protective layer allowing the digestive or immune processes to kill the parasite. 

If you were to look at DE under a powerful microscope you will see the sharp random edges of silica that do the damage, the particles look like minute shards of glass and get into the joints on the exoskeleton and as the insect moves it literally cuts them up.

Below: Diatomaceous earth varies in colour from white to brown.

The colour of diatomaceous earth has no bearing on how effective it was in our tests.

The Diatom is applied where insects live and move and will be picked up on the insect’s exoskeleton by static electricity. 

Unlike chemical pesticides results are not instant but may take several days, however the advantage of a natural product is that there is no egg withdrawal period necessary for poultry.

How long does it take for diatomaceous earth to work?

In my testing under ideal conditions the diatomaceous earth killed all the insects it was applied to within 48 hours.

Below: Red mites were killed in 24 hours under ideal conditions.

In a real world environment diatomaceous earth can be effective within 24 hours although better results are usually apparent after five days.