A rabbit in our yard had ... #176746
Asked April 23, 2014, 7:05 PM EDT
A rabbit in our yard had mange (we think he might be gone). Thinking about spreading diatomaceous earth around the yard to take care of any remaining bugs because we want to get new pets (cat and dog)and don't want them to get mange. We have lots of perennials in the yard too. Is spreading DE around a good idea? Don't want anything negative to happen. What do you know about DE?
Hennepin County Minnesota
Diatomite is used as an insecticide, due to its abrasive and physico-sorptive properties. The fine powder absorbs lipids from the waxy outer layer of insects' exoskeletons, causing them to dehydrate. Arthropods die as a result of the water pressure deficiency, based on Fick's law of diffusion. This also works against gastropods and is commonly employed in gardening to defeat slugs. However, since slugs inhabit humid environments, efficacy is very low. It is sometimes mixed with an attractant or other additives to increase its effectiveness. Medical-grade diatomite is sometimes used to de-worm both animals and humans, with questionable efficacy. It is commonly used in lieu of boric acid, and can be used to help control and possibly eliminate bed bug, house dust mite, cockroach, ant and flea infestations. This material has wide application for insect control in grain storage. In order to be effective as an insecticide, diatomaceous earth must be uncalcinated (i.e., it must not be heat-treated prior to application) and have a mean particle size below about 12 µm (i.e., food-grade). Since DE will not affect all insects and many are beneficial, you should treat only those causing a problem. Earthworms, ants, butterflies and predators should be protected. If the rabbit returns you can trap it but know that it is illegal to release them into other areas.
One more thing, Sarcoptic mange mites are usually spread by direct contact from host to host. While mites can live off of a host for days to weeks depending on their life stage, they are only infective for 36 hours, which means that environmental decontamination is generally not necessary. All the more reason to make certain the rabbit does not return.