Are cluster flies troubling you? Call us on
Cluster flies are one of my favourite pests due to the incredibly large numbers they arrive in, they are an interesting pest and often mistaken for the more common summer flies such as the House fly, Lesser House fly and Blue and Greenbottles, they are quite different and do not cause any problems in the late Spring and Summer months. But create havoc in peoples homes and businesses in the Winter.
Cluster flies are a hibernating fly and often associated with hibernating ladybirds that arrive at the same time or a little earlier, they enter the fabric of the house in the Autumn purely to hibernate, no breeding goes on during their hibernating period from Autumn to early Spring. They start to think about hibernation once the weather turns cooler, normally finally coming in when the temperatures average lower than 10 degrees Celsius, however for a few weeks and in warm years sometimes considerably more than a few weeks before this there can be lots of coming and going and flies getting into the house in spectacular numbers. Treatments can be done during this coming and going period to alleviate the problem but successful treatment is never achieved until the average temperature has dropped and all flies are hibernating.
Cluster flies can hibernate in lofts, cavity walls. sash windows, window reveals, in fact pretty much anywhere there is a small unused gap, the numbers coming into hibernate can be huge, thousands if not millions. Once in and settled if the weather warms up a little or they are on a South facing wall then they can start to wake up again and start to gain entry to the house during Winter months, sometimes in numbers so large it is jaw dropping!
Treatment is best achieved using a ULV sprayer an electronic fog sprayer with spray droplets less than half the size of an aerosol droplet, this treatment is great in most circumstances but not always successful, when it is not there are other methods at our disposal so that you do not have to contend with a constant stream of flies in the house throughout the Winter months.
An important tip with Cluster Flies is to know that once the flies have stopped coming into the living areas of the house and the temperatures have dropped to below 10 degrees then that is the optimum time to do the treatment, this goes against what you may think as for a period of time it will look like they may have gone, this is not the case and if treated then results will be far batter and more successful.