Steve from Athelstane, Wi writes
We've had a bad winter with cluster flies and want to improve our chances for next fall. Do we spray perimeter only or also indoors? Thanks.
You can go ahead and spray the exterior now to help stop the population from building but the actual exclusion sprays are recommended to start in August. Most of the exclusion applications are applied on the exterior of the structure though spraying inside and outside of window frames, door frames, and places where cables, pipes and wires enter in to the structure will double your chance of controlling the flies before they gather indoors.
Answer last updated on: 04/04/2013
