These are dark greyish flies about 8mm long with yellowish hairs on the back and with overlapping wings. In autumn they congregate in large numbers in upper rooms or roof spaces of houses to hibernate.
They will then reemerge in Spring to seek out egg laying sites outside. A mass of cluster flies has a characteristic smell. They are sluggish in flight and are a nuisance in the house.
The larvae of one species are parasitic upon certain earthworms, so this species is more common in rural areas.
Treatment:
There are a handful of control options for cluster fly. A fogging treatment may be deployed in infestations presenting high levels of activity. Licensed residual insecticide spray treatments may be used although due to the natural gaps within a roof space to aid ventilation, you may find that cluster flys return year on year.
Sometimes a fly zapper device may be successful in controlling cluster flies, this would be dependent upon a range of environmental factors.
The Bluebottle is a large buzzing fly with shiny, metallic blue body, 6-12mm long. One Bluebottle can lay up to 600 eggs, which in warm weather will hatch in under 48 hours and produce maggots which can become fully developed in a week. These maggots burrow into meat or carrion as they feed on it, and then pupate, often in loose soil, for about ten days before emerging as adult flies from the brown pupal case.
Bluebottles, like other flies, are often found on refuse tips, rotting animal matter, dirt and dustbins. They commute from filth to food and carry bacteria on their legs, feet and bodies.
Treatment:
It is important to locate the food source and remove it. This can range from unmanaged rubbish and waste to locating and removing a decaying carcass.
