Cluster Fly
Pollenia rudis
Identification
Cluster flies are slightly larger than house flies with golden hairs on their thorax. They invade homes in large groups during fall to hibernate in wall voids and attics. On warm winter days, they emerge inside the home, buzzing at windows. They don't breed indoors or contaminate food.
Treatment Cost
$150 - $350
Urgency Level
Low
Commonly Found In
Attics, wall voids, around windows, south-facing walls
Recommended Treatment
Professional exterior treatment in late August/September creates a barrier before migration. Interior treatment of attic and wall voids. Vacuum up active flies inside. UV light traps help in attics.
Prevention Tips
Seal cracks around windows and doors before September, screen all attic vents, caulk around siding and trim, schedule preventive exterior spray in late summer.
Frequently Asked Questions
How do I identify a cluster fly?
Cluster flies are slightly larger than house flies with golden hairs on their thorax. They invade homes in large groups during fall to hibernate in wall voids and attics. On warm winter days, they emerge inside the home, buzzing at windows. They don't breed indoors or contaminate food.
How do I get rid of cluster flys?
Professional exterior treatment in late August/September creates a barrier before migration. Interior treatment of attic and wall voids. Vacuum up active flies inside. UV light traps help in attics.
How can I prevent cluster flys?
Seal cracks around windows and doors before September, screen all attic vents, caulk around siding and trim, schedule preventive exterior spray in late summer.
How much does cluster fly treatment cost?
The average cost of professional cluster fly treatment ranges from $150 to $350 in Quebec, Canada.
Where are cluster flys commonly found?
Attics, wall voids, around windows, south-facing walls