What is Diatomaceous Earth?
It is the natural fossilized remains of diatoms, which are remains of a small aquatic organisms. Their skeletons are made of a substance that are small and sharp. To the naked eye looks like a powdery substance. The great thing about Diatomaceous Earth (DE) is that it produces injury to insects my mechanical process. Under the microscope DE has sharp edges, and it is very abrasive to insects. When they crawl over it, their exoskeleton gets damaged, loosing moisture. They will basically dry out, and die of dehydration. It works very well when is applied on dry surfaces. It basically remain effective indefinitely, as long as it is kept dry.
Diatomaceous Earth Uses
There are two types of diatomaceous earth. One is food grade, which is the most commonly used around vegetable gardens. I use this type to kill ants around my house. It works well when sprinkled along the kitchen counter. Diatomaceous Earth is a great product to control a big number of common pests like spider mites, house flies, ticks, ants, and I have seen people using it for grub control. It will not kill the grubs that are already on the lawn, but it can kill the beetles that come in contact with the DE. Therefore preventing the grubs from laying eggs on the lawn. I would probably not use it as grub control. I would rather use compost and compost tea to control grubs.
However, there is another type of DE that is kind of dangerous. This one is pool grade that has been heated turning the silicon dioxide that is present in the DE into crystalline silica. Some studies show it can contain up to 75% silica, which is really harmful for humans if inhaled. You can get confused if you buy pool grade Diatomaceous Earth because is much cheaper, but this specific grade should not be used other than for pool filtration, because of its high content of silica. Food grade will contain approximately 1% silica.
What products do you use to control insects around your property? Have you ever used Diatomaceous Earth?