North American Fruit Explorers mailing list at ibiblio

["Lon J. Rombough" <lonrom@hevanet.com>]

Title: Re: [NAFEX] Re: Poisonous Plants

The explanation I've always heard for the effectiveness of diatomaceous earth is that those sharp spicules cut the waxy cuticle on an insect's exoskeleton, allowing them to dessicate to death.

> Doreen posted:
> "The best thing I've found for deterring earwigs is diatomaceous earth.  You
> can buy it in 4-lb. sacks where organic garden supplies are sold.  Sprinkle
> the powder around the base of trees and everywhere there are earwigs
> present.  They get the powder on their feet, it travels into their guts and
> they dehydrate.  Damage on my berries stopped when I spread it.
> Doreen Howard"
>
> I thought it acted to plug up the insects' respiratory spiracles.  I've
> heard it works on intestinal worms as a vermifuge by penetrating their
> tender little bodies.  Some of the "Earth Children" may have used it for
> this purpose. Under the microscope it looks like what it is; remains of
> diatoms, some with sharp spicules but most are tiny siliceous particles.