Quote from: Julie Marie on June 20, 2011, 01:36:40 AM
But if you simply lay out a dusting of diatomaceous earth, your problems will soon be over. Insects like ants and roaches walk over the fine powder and it abrades their exoskeletons and kills them through dehydration. It's kind of like sliding over broken glass. And they can't build up an immunity. Also they carry the stuff with them back to the nest. More rolling around in broken glass. 
Kia Ora Julie,
It's true the mode of action of DE is to act like a "sponge", it absorbs the protective oily/waxy substance on the insect's cuticle...However unless one can actually coat the individual insect with the dust, they [in particular the Germany cockroach] will avoid it, they have a tendency to avoid any dusty areas because the dust [any dust] tends to clog/block their spiracles [breathing holes on the side of their bodies']...
When I first took an interest in urban pestology[I was living in Australia at the time and I was quite fearful of what I didn't understand... So in order to over come this fear, I became an urban pestologist=studying vertebrae and invertebrate pest of the urban environment ], there were all these new synthetic insecticide on the market, companies had started to move away from the more natural slow acting "proven" products, but nowadays we have have come a full cycle where the likes of Boric acid and DE are now the "new old" new wonder products...
Basic entomology can be interesting and fun, 
but finding out how insects live, is not for everyone. 
Some people have a phobia, about things that creep and crawl, 
but if they took time out to study them, they would have no fear at all. 
Metta Zenda
