Diatomaceous earth is an all-natural, safe-to-use substance that doesn’t harm plants with toxic chemicals. The nature of diatomaceous earth makes it useful against most types of insect infestation you might be experiencing; and unlike chemical insecticides, insects can’t develop a resistance to the effects of DE. So once they’re gone, they’re gone for good. DE is an abrasive. and when used as an insecticide, it gradually scrapes away an insect’s exoskeleton, absorbs the fluids, and dehydrates insects and other critters to eventual death.