Flies
The Common Housefly and the Lesser Housefly are the most widespread household flies.
The adult is 7-8mm long, grey in colour with black stripes on the back, with a single pair of veined membraneous wings.
The large compound eyes take up most of the head and are wider apart in the female than the male of the species.
The smaller Lesser Housefly, rejoicing in the scientific name Fannia canicularis, is the one that cruises around light fittings, abruptly changing direction in mid-flight.
The Housefly has a sticky pad on each of its six hairy feet, and these enable it to walk upside down on ceilings or crawl up windows.
Houseflies complete their life cycle of egg, maggot, pupa, adult, in a week during warm weather.
The eggs are laid in batches of about 120 on any rotting organic matter and the legless white maggots burrow into this food until ready to pupate in loose soil or rubbish.
The answer to “where do flies go in the winter?” is that some hibernate, but most pass the winter in the pupal stage.
Houseflies may transmit a wide range of bacterial diseases.
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.
Cluster Flies, 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.
Fruit Flies, a family of very small (about 3mm) flies, some with prominent red eyes, characterised by a slow hovering flight in which the abdomen hangs down.
All are associated with rotting fruit and vegetables or fermenting liquids. One species breeds in sour milk, for example, in the residue of forgotten milk bottles.
Midges, tiny dark grey flies, only about 2mm long with hair-fringed wings, most prevalent in spring and summer near sewage works.
Also known as Filter Flies or Owl Midges, their grubs perform a useful purpose because they break down organic material at sewage works.