Michael from Winnsboro, Tx writes
I sprayed under my house for spiders and was wondering how long its effectiveness will last?
Martins Permethrin 10% will likely last up to about 30 days in optimum conditions. If you would like a longer lasting insecticide, we would recommend an encapsulated product such as Cyzmic CS. In a crawl space, you could also use an insecticide dust such as Delta Dust, which is a dry formulation that lasts about six months.
Answer last updated on: 03/25/2018