June…why so many flies?
One of the downsides of summer is the problem that the warm weather brings so many flies and flying insects with it, especially even more so after a wettish spring time. And it is not just the problem of lots and lots of one kind of fly, it is the vast numbers of different kind of fly - each one having its own distinct life cycle and home.
Outside many back doors nowadays there will be a small bin into which all of the fruit and vegetable remains will be put. On a hot summer’s day this will start to break down into a semi-liquid soup…first of all it will attract the fruit, or vinegar, flies - the tiny little yellowish brown flies with bright red eyes, about 3mm long. These will appear almost overnight and great clouds of them will erupt from the compost bins…try leaving a glass on the patio overnight with a little drop of fruit juice residue in the bottom and you will see how quickly these flies will appear!
If the recycling waste bin is not regularly emptied, or the bins are not collected frequently, the vegetable matter will break down even further and this moist matter will provide a breeding ground for the common house fly. These flies can complete their entire life cycle in six days in favourable summer conditions and if they have laid their eggs in the right place. If it is really right, the eggs will hatch in eight hours. The larva will take between three and 60 days to develop, then they pupate - a stage that will last for three to 28 days, and then the adult emerges. The adult fly lives for between four to 12 weeks. Eggs start to be produced after two days, at a rate of 150 a day and just eight grams of high-protein residue will support all of these eggs to adulthood.
Most of us will recognise the flies that fly in triangular pattern around the hanging light fittings. These are the males of the lesser house flies which also lay their eggs in semi-liquid, decaying matter. The number of these flies can increase as they can overwinter in the larval, pupal or the adult stage.
Try leaving a fresh chicken joint open next to the barbecue or in the kitchen on a hot day - it will not take long for a bluebottle to find it and you will within minutes see a batch of little creamy, white eggs laid on the surface of the meat.
If the guttering around the house, or the drains, has got a small blockage or some standing water…then little filter flies will start to appear. These are also known as sewer flies, and owl midges…and, of course, standing water like this will provide a breeding ground for the ever-annoying mosquitos.
Later on in the year, come the cluster flies. These lay their eggs in the soil and the larvae hatch out and burrow into earthworms. In the autumn, these flies come out of the soil as adults and get into loft spaces and top-floor rooms in their hundreds and thousands where they will appear to be very slow and sluggish. If they overwinter in the loft, they will appear again in spring and start the whole process over again.
Then there is the autumn fly, the yellow swarming fly, the horse fly, the flesh fly….and, of course, the wasp - but that is another story…..