What All Does Diatomaceous Earth Kill?
Diatomaceous earth (DE) is a naturally occurring, silica-based sedimentary rock composed of the fossilized remains of diatoms, a type of hard-shelled algae; it’s a powerful, natural killer of various insects and parasites that have an exoskeleton. Its effectiveness stems from its ability to absorb lipids from the waxy outer layer of these creatures, causing them to dehydrate and die.
The Broad Spectrum of Diatomaceous Earth’s Killing Power
Diatomaceous earth, specifically food-grade DE and insecticide-grade DE, is effective against a wide array of pests due to its abrasive and absorbent properties. This isn’t a broad-spectrum poison, but rather a physical control method, which means it targets creatures based on their physiology, primarily those with exoskeletons.
Food-grade diatomaceous earth is generally considered safe for human and animal consumption, making it suitable for use in and around the home, garden, and livestock environments. Insecticide-grade diatomaceous earth, on the other hand, may contain a higher concentration of crystalline silica, posing a greater inhalation risk.
Specifically, DE is known to kill:
- Crawling Insects: This includes ants, bed bugs, cockroaches, fleas, earwigs, silverfish, carpet beetles, and dust mites.
- Garden Pests: Common garden invaders like aphids, spider mites, squash bugs, cucumber beetles, and various caterpillars can be controlled with DE.
- Internal Parasites in Animals: Food-grade DE is sometimes used as a dewormer for livestock, poultry, and pets, targeting parasites like roundworms, whipworms, hookworms, and tapeworms. The evidence regarding its efficacy as an internal dewormer is mixed and requires further research.
- Stored Grain Pests: DE is highly effective against grain weevils, flour beetles, and other insects that infest stored grains.
- Slugs and Snails: The abrasive nature of DE irritates and dries out these soft-bodied pests.
It’s crucial to note that DE is most effective when dry. Rain or moisture will reduce its effectiveness, requiring reapplication. Also, DE is not effective against all types of insects. For instance, insects with a thick, impenetrable exoskeleton may be less susceptible. Honeybees and other beneficial insects can also be harmed, so careful application is necessary to minimize non-target effects.
Understanding the Mechanics of Diatomaceous Earth’s Lethality
The Dehydration Process
The primary mechanism by which DE kills insects is through desiccation. The microscopic, sharp edges of the diatom fossils abrade the insect’s waxy cuticle, the protective outer layer that prevents water loss. This abrasion allows DE to absorb the lipids from the cuticle, disrupting its waterproofing ability. As a result, the insect loses moisture rapidly and dies from dehydration.
Abrasive Action and Physical Disruption
Beyond dehydration, the abrasive nature of DE can also cause physical damage to the insect’s exoskeleton and internal organs. This damage weakens the insect, making it more vulnerable to dehydration and other environmental stressors.
Distinguishing Between Food-Grade and Insecticide-Grade DE
It’s essential to differentiate between food-grade and insecticide-grade DE. While both are composed of diatomaceous earth, insecticide-grade DE typically contains a higher percentage of crystalline silica. Crystalline silica is a known human carcinogen when inhaled in large quantities. Therefore, insecticide-grade DE should only be used outdoors or in areas where human and animal exposure is minimized, and appropriate respiratory protection should always be worn during application. Food-grade DE, containing a much lower level of crystalline silica, is considered safer for use around humans and animals, including ingestion.
Frequently Asked Questions About Diatomaceous Earth
What is the difference between food-grade and pool-grade diatomaceous earth?
Pool-grade DE is specifically processed for use in swimming pool filters. It is not safe for human or animal consumption and should never be used as an insecticide or dewormer. Pool-grade DE contains a very high concentration of crystalline silica and is a significant health hazard if inhaled. Food-grade DE, on the other hand, undergoes a different processing method, resulting in a much lower concentration of crystalline silica.
How long does it take for diatomaceous earth to kill insects?
The time it takes for DE to kill insects varies depending on factors such as the type of insect, the amount of DE the insect comes into contact with, and environmental conditions. Generally, insects will begin to die within 24 to 72 hours after exposure to DE.
Can diatomaceous earth kill bed bugs?
Yes, diatomaceous earth is effective against bed bugs. It works by damaging their exoskeletons, causing them to dehydrate and die. Apply a thin layer of DE to areas where bed bugs are likely to hide, such as around bed frames, mattresses, and baseboards. Multiple applications may be necessary to eliminate the entire infestation.
Is diatomaceous earth safe for pets?
Food-grade diatomaceous earth is generally considered safe for pets when used as directed. It can be used externally to control fleas and ticks, and some pet owners use it internally as a dewormer. However, it’s crucial to consult with a veterinarian before giving DE to your pet, especially if they have any underlying health conditions. Always use food-grade DE, never pool-grade or insecticide-grade. Be mindful of potential respiratory irritation, especially for sensitive animals.
How should I apply diatomaceous earth to my garden?
For garden pest control, apply DE as a light dusting on plants, soil, and affected areas. It’s best to apply it in the morning or evening when plants are less likely to be stressed. Reapply after rain or watering. Avoid applying DE during windy conditions to prevent it from blowing away.
Does diatomaceous earth kill fleas?
Yes, DE can kill fleas. Dust a thin layer of food-grade DE on carpets, pet bedding, and other areas where fleas are present. You can also rub a small amount of DE into your pet’s fur, being careful to avoid their eyes and nose.
Can diatomaceous earth kill roaches?
Diatomaceous earth is effective against cockroaches. Apply it in areas where roaches are known to travel, such as along baseboards, under sinks, and in cracks and crevices.
Does diatomaceous earth kill ants?
Yes, DE is effective against ants. Follow ant trails with a light dusting of DE to disrupt their paths and kill them as they walk through it. Focus on entry points to your home.
Is diatomaceous earth harmful to humans?
Food-grade diatomaceous earth is generally considered safe for humans when used as directed. However, inhaling DE dust can cause respiratory irritation, so it’s important to wear a mask during application. Avoid getting DE in your eyes, as it can cause irritation.
How should diatomaceous earth be stored?
Store DE in a dry, airtight container to prevent it from absorbing moisture and losing its effectiveness.
Can diatomaceous earth be used on edible plants?
Yes, food-grade diatomaceous earth can be used on edible plants. Just be sure to wash the plants thoroughly before eating them.
Does diatomaceous earth kill bees?
Yes, diatomaceous earth can harm bees. Bees are beneficial insects, so it’s important to avoid applying DE directly to flowers or areas where bees are actively foraging. Apply DE strategically and carefully to minimize harm to these important pollinators. Consider alternative pest control methods if bees are abundant in your garden.