Bed bugs, cockroaches, crickets, fleas, ticks and spiders sit on the label, and the pests diatomaceous earth kills all share one habit. They walk. The National Pesticide Information Center lists those six as registered targets. Extension pest notes add carpenter ants, carpet beetles, silverfish and firebrats. If a bug never crosses a dry film of your dust, that bug is out of range.
The plastic bulb duster wheezes when you squeeze it, and a gray cloud drifts behind the baseboard and settles in a film you can hardly see. I checked that line a week later with a flashlight. The film was still there, and I noticed one scuffed track where something had crossed. The dust is not poison, and nothing has to eat the stuff to die. Your powder only reaches bugs that walk into the film. The roach using that gap picks up a load, and the roach running the wall an inch (2.5 cm) higher never touches a grain.
That target list has a shape you can predict. Diatomaceous earth is a contact insecticide, and the powder pulls moisture out of an insect while the sharp grains scratch the exoskeleton, so the bug dries out and dies. Soft bodies and hard shells both go down that way. Crossing the dust is what puts an insect in range, which is why the label reads like a roll call of crawlers. A wasp flying past your porch light is untouched. So is a beetle whose route runs two feet (60 cm) from where you dusted.
Registered against is not the same as wiped out. One trial ran two dusts side by side under permanent exposure. The pest-management product hit 100% bed bug mortality by day 10. The supermarket dust reached 15%. Same bug, same active ingredient, and the results are not close. On wheat, dust alone at 150 ppm killed 27.76% to 41.33% of four stored-grain beetle species in 7 days, and 38.55% to 53.21% by day 14.
Nothing in that work puts a number on cockroaches, crickets, ticks or spiders. A registered use tells you the label covers that pest, and you get no mortality figure with it. The gap is not proof the dust fails on ticks, and you have a fair reason to keep your expectations modest and watch the result in your own house.
Diatomaceous earth for fleas runs on that same rule, and some products are labeled to go straight onto dogs and cats. Read the label on your bag first, because that clearance is product by product. The rest is placement. Put the dust where your animal sleeps and along the runs it uses, then leave the line alone. Both trials measured kill over days of steady contact, not minutes.
Treat a registered-use list as a starting point rather than a promise. A listing tells you the pest is in range of the dust, and the bed bug figures show how far apart two products with the same claim can land. Buy a dust sold for pest control, lay it on the path your bugs use, and give it a week or two before you judge it. The pests diatomaceous earth kills are the ones that keep walking through your dust, so a spreading bed bug problem still needs more than a powder.
Read the full article: Diatomaceous Earth: What It Really Kills
