Lori from Michigan writes
D-Fense SC is a great choice as part of a cluster fly control program. The best time to treat for this overwintering pest is in late summer and fall when this pest is trying to move indoors to stay warm during the winter. You can treat during warm spells and in the spring as cluster flies move to go back outside, but you will not be able to completely eradicate them during this time. We also recommend sealing up cracks and crevices around windows, doors, and light fixtures where these insects may be able to enter or hide. Many folks will also use a fly light to help catch these insects in indoor areas. Please take a moment to look over our article on How To Get Rid of Cluster Flies for more information.
Answer last updated on: 02/19/2018
