Cluster Flies

If you have lots of flies in your loft or gathering around windows particularly in the Autumn you may have a cluster fly problem.

Call us now for a no obligation quote or if you would like to know more about Cluster Flies and what we do read on.



 A Cluster Fly

There are a number of different flies that cluster these are


Green Cluster Fly Dasyphora cyanella

Yellow swarming Fly Thaumatomyia notata

The Cluster Fly Pollenia rudis

The Autumn Fly


The Cluster Fly Pollenia rudis is the most common fly we get called to treat.


                   Cluster Fly In a loft       Cluster Fly patches in a loft                              


As you can see from the pictures above these flies can gather in large numbers in the loft,


The larva (maggot) lives as a parasite of the earthworm Allolobophora chlorotica 


The adults lay eggs on the open ground which after about a week hatch. The newly hatched larva hunt out finds the earthworm and bores into it slowly developing inside it devours the earth worm and eventually pops out of the earthworm and pupates.


As the now young adults emerge  from the pupa they can often be seen sunbathing on south facing walls and fences.


With the onset of Autumn the adults try to enter buildings to over winter and can gather in there thousands in lofts,roofs, upper bedrooms and window casements. When the weather is cold little or no activity can be seen, but on warm sunny winter days they become more active and gather on sunny spots again to sun themselves. In most years there are two generations but when summers are long and warm there can be four. Weather plays a large role in when the flies start to seek out a place to overwinter and again some years it can be as late as December.


Cluster Flies do not damage buildings except for causing staining in the areas in which they cluster. As the flies do not feed on fecal matter and are not interested in Human food sources they do not present the same health risks as other flies but their presence alone in large numbers particularly in upper rooms can cause real distress.


We can carry out treatments of loft spaces and window frames to help alleviate the problem of cluster fly. Call us today to discuss the treatments we can carry out.


Don't delay

Call Today

They're not going to go away ! 

0800  612 6942


We carry out cluster fly treatments in Somerset and Devon.