Debi writes
Diatomaceous Earth will kill spiders (including brown recluse spiders), but it works over a period of several days and will not provide a fast knockdown. Diatomaceous Earth will also kill most other insects that come into contact with treated areas which will eliminate the spiders food source. By eliminating the spiders food source, existing spiders will move or starve to death (even if they do not come into contact with treated areas) and new spiders will not move in.
Answer last updated on: 03/25/2011