Leyli from Portland, Maine writes,
Once Evergreen dust is applied inside walls, crevices, electrical boxes, how long does its potency last?
We are trying to create barriers against bed bugs between apartments in multi-unit buildings and don't want to reapply constantly. Diatomaceous earth works forever as long as it doesn't get wet but doesn't have the instant kill that this dust has.
Evergreen Pyrethrum Dust 1% can last for up to 4-6 months depending on where it was applied. You should also note that Evergreen Pyrethrum Dust 1% dust does not have an immediate kill (all dusts take time to kill insects), and it can take about 3 days for insects to die after they have come into contact with treated areas. And while it is true that Diatomaceous earth can last indefinitely it will still need to be reapplied as it becomes covered with other dust or debris.
Answer last updated on: 09/20/2011