Flies

All images on this website have been taken in Leicestershire and Rutland by NatureSpot members. We welcome new contributions - just register and use the Submit Records form to post your photos. Click on any image below to visit the species page. The RED / AMBER / GREEN dots indicate how easy it is to identify the species - see our Identification Difficulty page for more information. A coloured rating followed by an exclamation mark denotes that different ID difficulties apply to either males and females or to the larvae - see the species page for more detail.

Flies

True flies (order Diptera) are an immense group with over 100,000 known species. They all have their hind pair of wings reduced to pin-shaped structures called halteres which act as gyroscopes to maintain balance in flight. Most feed on liquids, including nectar and blood.

The Dipterist's Forum offers a huge range of support for those interested in this group.

The families in the gallery below represent flies that are in the dipteran sub-orders Brachycera and Cyclorrhapha which are 'higher' flies, meaning later to evolve than the Nematocera which are displayed in the Craneflies, Gnats & Midges gallery. All families are displayed in taxonomic order. Note that Hoverflies (Syrphidae family) are displayed in a separate gallery.

Click on the headings below to expand/contract the text.

Rhagionidae - Snipe flies

Rhagionidae are medium to large flies with slender bodies and stilt-like legs. The mouthparts are adapted for piercing and many species feed on blood, whilst others are predatory on other insects. They are typically brown and yellow flies, and lack bristles. The larvae are also predatory and are mostly terrestrial, although some are aquatic. Snipe flies in the genus Rhagio are sometimes called "down-looker" flies after their habit of perching head-downward on tree trunks.

Tabanidae - Horse flies

These are large flies which can give a painful bite. Adult horse flies feed on nectar and sometimes pollen but females require a blood meal for reproduction. Males lack the necessary mouth parts for blood feeding. Most female horse flies feed on mammal blood, but some species are known to feed on birds, amphibians or reptiles. Unlike insects which surreptitiously puncture the skin with needle-like organs, horse flies have tiny, serrated mandibles which they use to rip and/or slice flesh apart.

Xylomyidae - Wood-soldierflies

Stratiomyidae - Soldier flies

This family are called soldier flies because of the bright, often metallic colours and regular patterns.

Identification guides for soldierflies and their allies

Acroceridae - Spider parasite flies

Bombyliidae - Bee flies

The adults resemble bees which may give them some protection from predators. The larvae are predators or parasitoids of other insect eggs or larvae, and are often opportunistic in which species they attack.

Therevidae - Stiletto flies

The larvae of this family are predators of insect larvae in soil

Asilidae - Robber flies

Most Robber flies are bristly and have a 'moustache' of bristles on their face to protect them when attacking prey. They have a short, strong proboscis, used to stab and inject victims with saliva containing neurotoxic and proteolytic enzymes which paralyze and digest the insides; the fly then sucks the liquefied meal through the proboscis.

Britain's Robberflies - Malcolm Smart Excellent illustrated presentation covering UK species.