Hover Flies

 

BACK TO

 

What Are Hover Flies ?

Hover Flies ( sometimes known in America as Flower Flies ) belong to a large family of small to big flies. They are true flies, with only one pair of wings.( Theses flies have one pair of wings, and the wasps and bees have two pairs ) Hovering is their speciality although other flies can also hover.

They are among the most frequent visitors to flowers in the garden. In Holland and Belgium alone over 300 species exist!. In Britain About 270 species are known at present many can migratet like butterflies with powerful flight such as the Red admiral or Painted lady.

Many are seen in the summer season in number mixing with butterflies, bees, bumble bees and other flower dependent insects. Some species are useful to the gardener since their larvae eat pest aphids on garden plants and crops.

What is the purpose of the Bright bodies and patterns ?

Many of the of hoverflies have pretty body patterns, often of black and yellow, to mimic wasps and bees but are harmless.Hover fly mimicry include warning coloration of yellow and black, a narrow waist like a wasp and even the ability to mimic the stinging action of a wasp, by pushing the tip of the abdomen into your fingers if they are caught and held. They do not sting and are harmless.

 

 

Their fast flight, the standing still on flight and, in some species, their size are remarkable. Some hover flies are among the biggest flies of Central Europe. Many species are very colorful as well. It is not always that easy to identify them being hover flies. Some thick-headed flies and bee flies are quite similar. Besides some hover flies are very dark creatures and these colors makes it hard to identify them correctly.

 

What is the easy way to confirm if a Fly is a Hover ?

To confirm an insect is a Hover an examination of wing veins is necessary the veins in the wing and In Hovers a great part of the edge of the wing is without veins. The vein running all te way to the edge in most flies, only reaches the last transverse vein, not the edge in hover flies (A). Another feature of hover flies is the so-calles 'floating vein' (B). This vein just ends nowhere. Usually veins end either at the edge of the wing or in another vein. Both these features being present means you are actually looking at a hover fly.

Where so they complete their Life - Cycle ?

Like other flies Hovers go through all stages of insect life: egg-larva-pupa-imago. The larvae of hoverflies are remarkably diverse for just one family of flies.

Some have adapted to aquatic life live in extremely dirty water (including stale), eating all kinds of decaying materials. In order to breath they developed a long pipe at the rear end of the body, which they stick into the air. including the rat-tailed maggots (about 40 species).

Other larvae hunt for plant lice.or aphids. Over one third of hoverflies have larvae that eat aphids (over 110 species).

Some live in decaying wood, or sap runs on live trees (33 species).

Some are a pest in agriculture eating live plant tissue such as roots, stems and flower bulbs from within or as leaf miners (about 30 species).

This group is useful fevaluating site ecology, being a day active, with a varied range of larval habitat specialisations

 

What do the Eat ?

They aree one of the few types of insects that can digest pollen, which is rich in protein for development of the eggs. The surface coat of Pollen has is resistant to most insect digestive juices. The yellow patternation can reflect the ammount and type of pollen the insects have eaten

 

Sexing Hover Flies

Like with so many other flies males and females often look alike, having the same coloring, size etc. Exceptions are found especially among the drone flies, where females differ from the males. However it's always easy to tell males and females apart. Like all other flies the males have much bigger eyes. These eyes almost touch eachother in the middle. Females have much smaller eyes, placed farther apart.

 

What is the definitive Reference on Hovers ?

1.Stubbs, A.E. British Hoverflies An Illustrated Identification Guide 469 pages, 12 col plates, b/w illus.British Entomological and Natural History Society [ISBN: 1899935053]. 276 species are described and their identification is made easy by the extensive keys, which incorporate over 640 line drawings. The 12 superb colour plates by Steven Falk show 263 specimens depicting 190 different species.Good information on the family

2. Maps of distribution and analysis of flight periods are published in a BRC atlas:- Ball, S.G. & Morris, R.K.A., 2000. Provisional atlas of British hoverflies (Diptera, Syrphidae). Biological Records Centre, Huntingdon.