<p>An insecticide including diatomaceous earth in a liquid mixture of water and one or more additives is provided. The diatomaceous earth may be present in an amount between at least 20 and less than 25 weight percent of the insecticide. The insecticide is applied in liquid form to surfaces for controlling the spread of insects. The liquid component of the insecticide evaporates leaving a thin layer of the dried diatomaceous earth. Insects traversing the diatomaceous earth layer are scratched and scraped by the layer, which results in water loss from the exoskeleton and eventually death.</p>
