Hoverflies, Flower Flies (Syrphidae) One of their characteristics is their bee, wasp or bumblebee mimicry, whereas they are completely defenceless. Flower flies cannot sting.  They have same the bright colours, and sometimes the dense hair covering of bumblebees. 
Hovering is a speciality, but they are also fast and very manoeuvrable.
The difference with other flies is the spurious vein. This vein neither ends nor connects with other wing veins. The spurious vein just ends for the edge of the wings.  
Cell 2 is closed. The closed cell 4 is longer or as long as one third of the length of the wing.

The arista is on the side of the third antennal segment. Not on the top.
On the thorax are no stiff hairs like other flies.

       
Wing of a Meliscaeva auricollis                                                                          Antenna of a volucella zonaria

   Wing:
   1, 2, 3, 4: closed cell
   a: vena spuria or a false vein
   b: stigma 
   c: cross vein
   d: outer cross vein

   Antenna:  
   1: third antennal segment (you can't see the other two on this photo)
   2: arista

Females have smaller eyes which are placed farther apart. The eyes of the male meet at the top of the head. Of course there are exceptions.Than you have to look at the underside of the abdomen, males have curbed asymetricla genitalia. The abdomen of the female is more pointed with inconspicuous genitalia.
Many species feed mainly on nectar and pollen. The larvae (maggots) eat a wide range of foods.

Exceptions 
No vena spuria: Eristalinus sepulchralis and Psilota anthracina.
Arista op the top: Callicera and Ceriana
Stiff hairs: Ferdinandea. Less: Volucella, Cheilosia, Brachyopa and Chamaesyrphus.

(Information from: Zweefvliegtabel van Aat Barendregt)

Another larvae out of the pond. Photo 3-4-2010.

The Eristalis pertinax is almost similar to the Eristalis tenax  but has no rows hairs on the eyes. And the lower part of a leg is yellow. The abdomen of males is slightly conical.
Lengte 11 - 15 mm.
January - December.

Eristalis feed on nectar and pollen

The larvae are rat-tailed maggots. 

Europe but it has been introduced into North America and is widely established.

German: Gemeine Keilfleckschwebfliege  French: Eristale opiniâtre

The Eristalis tenax has two vertical stripes on the eyes (actually hairband). If it flies, it lets the hind legs hanging down. 
The adult females hibernate.

Length: 14 - 16 mm. 
January - december.

German: Scheinbienen, Keilfleckschwebfliege French: Eristale gluante

It is very similar to the Eristalis interrupta but it has no clear wings. 
The yellow rings on the abdomen, the yellow  spots and the dark band on the wings are characteristic.

April - October

It is be found especially near forests.
The larvae live in the water.

German: Garten-Keilfleckschwebfliege

Length: 9-11mm, March-October.

Photos below: Eristalis arbustorum or Eristalis abusiva.

German: Kleine Keilfleckschwebfliege (Eristalis arbustorum)
French: Eristale des Arbustes (Eristalis arbustorum)

German: Mittlere Keilfleckschwebfliege

It's a springfly.. 
The first yellow band (sometimes separately) is broader than the yellow band (also interrupted) Sometimes there is also third band.
A copper colored thorax with a beautiful gloss.

They occur in forest edges and shrubs.
In my garden it likes to sunbathe on the leaves on the Deutzia.

As  you can see on the photos, there is a difference in bands.
Length: 9 - 11 mm.
April - June.

German: Zweiband-Wiesenschwebfliege

A larger species than the Epistrophe eligans. The broad bands are yellow orange. The thorax is less shining. But the fly also has a beautiful gloss
The shape of the bands of the male is different. 
In April 2009 for the first time in the garden.

Length: 11 - 13 mm.
April - June.
The larvae  feed on aphids

Epistrophe flava male
    

Explanation Han Endt (translated): Thijs, to your earlier observation, you see the vague light stripes on the thorax very well. Also, the shape of the double spots on second tergite  is not the same. (He compared to the photographs of the female Epistrophe flava.

The yellowish white eyes are covered with numerous, small, dark spots.
It has stripes on the thorax. In the middle the abdomen is dull. Furthermore, it is shiny.
The rear legs are curved.
It is a common hofly. It has a preference for moist areas.
In April 2009 I saw it for the first time in the garden..

In the Netherlands there is also the Eristalinus aeneus. This fly is completely shiny and lacks the clear long stripes on the thorax.
There are many more species outside the Netherlands.

Length: 9 - 11 mm.
April - September.

German: Schwarze Augenfleck-Schwebfliege

Myathropa florea Family Myathropa

Ofcourse it looks like a honey bee.
It has a distinctive pattern of grey bars on the top of the thorax. The Dutch name is skullhoverfly because of this pattern.

Variable in size:10-14 mm.
April - October.

They occur in forest edges and shrubs.

The larva is a rat-tailed maggot, with a long and telescopically extendible breathing tube which enables it to breathe whilst submerged in water-filled cavities full of dead leaves

German: Totenkopfschwebfliege French: Eristale des fleurs

Below: The spots of this Didea fasciata are less curved.
  

Leucozona glaucia  Family Leucozona

Usually you can find the Leucozona glaucia on a white Apiaceae or Umbelliferae. They always run back and forth. That's why, they were difficult to photograph. The eggs are also on these plants.

They are especially along forest edges in deciduous forests.
Length 11 -13 mm
June - September
The larvae  feed on aphids.

Narcissus fly, Greater bulb fly  (Merodon equestris) Family Merodon

The hairs have different colour forms. It has strong, black legs. 
Length: 12 - 14mm
April - July. 
Woods, hedgerows, parks and gardens.
Eggs are laid at the base of (especially) bluebell or daffodil foliage. The larvae follow the foliage down to the bulb and grubs tunnels into the bulb.
Similar species: Volucella bombylans (no U-shaped bend in the veins) and Eristalis intricaria (legs are partly pale)
    
Without black hairs and with many black hairs.

German: Narzissenschwebfliege

White-banded Drone Fly (Volucella pellucens) Family Volucella
It has a broad body. It is mainly black, but the front part of the abdomen has a broad yellow, white band.  
It is usually found in woodland, but will enter gardens.
It lives on nectar and pollen
Length: 12 - 18 mm.
May - September.
Europe, Asia, Japan

The female enters the underground paper nests of the common wasp Vespula vulgaris, or the German wasp, Vespula germanica, and lays her eggs.  The larvae  feed on all kind  of waste and even dead wasp grubs and adults.
Fully grown larvae leave the nest and pupate in the soil below.
Family of the Volucella zonaria.

German: Gemeine Waldschwebfliege French: Volucelle transparente

I haven't seen the Volucella zonaria in large numbers in the garden. It is a big hoverfly. You don’t overlook it.  
It is a summer guest. Not a bird of passage but a hoverfly of passage. 

The larvae grow up in a wasp nest, where they feed  also on dead wasp larvae. 
Length: 18 - 22 mm.
June - October.

Family of the Volucella pellucens
                    
On the tabel August 2008.  June 2009: male

German: Hornissenschwebfliege,  Große Waldschwebfliege, Riesen-Hummelschwebfliege

Eristalis intricaria Family Eristalis

It is an Eristalis, but it looks more like a bumblebee. The legs are black with white pieces (knee, tar). The shield is lighter. The males are usually sandy-haired. The females have black on tergite 2 of the abdomen and white at the tip of the abdomen.
The larva is a rat-tailed maggot.

It's an early hoverfly. (March - september) But I saw the first end of July.

Length: 11-14 mm
March - September.

  Photos 14-4-2010 Eristalis intricaria male

German: Hummel-Keilfleckschwebfliege, Pelzige Mistbiene   

Heineken Hover Fly (Rhingia campestris) Family Rhingia

This fly is easy to determine with its snout. But you have to know, it belongs to this family. For it does not look like a hover fly.
The larvae live in dung, especially in cow dung. That is not in the neighbourhood of my garden. Therefore where this fly is born, I don’t know.  

Length: 7 - 11 mm.
April - October.

These flies also are difficult to recognize as a hoverfly. This is because the dull gray thorax. The abdomen, scutellum and eyes are striking red orange. It is the only hoverfly of the family with reddish brown shoulder humps.
Used to be in the Netherlands in the dunes. Now also in other arias of the Netherlands.
The larvae of this family live in decaying sap on and in the bark of trees. The flies of this family are often nearby such places. The Brachyopa scutellaris also can be found on flowers.

Length: 6 to 8 mm.
April-June.
Europe

Larvae are found in the roots of thes plants. 

Length: 9 -11 mm.
May - August.   

A common species on the sandy soils It can be found at sunny spots along the forest. 
A large cheilosia with black legs and antennae.
The larvae live on Scrophularia

Length: 9 -12 mm.
April - August.

female

German: Gemeine Erzschwebfliege

First I thought it was an ordinary fly. But at the way of flying it is to recognize as a hoverfly.
He has some grey spots on the abdomen

De larva is a leafminer.
The other Cheilosia  species aren't leaf-miners. It is a miner on Navelwort (Umbilicus rupestris) and Orpine (Sedum Telephium) 

Length: 8 - 10 mm.
March - May.

Length: 8 - 10 mm.
April - September.

Yellowish hairy, hairless eye. Legs partly yellow. Wide center knot. The scutellum of the female is yellow.
Open forests, mostly sand.
Larvae in mushrooms. In particular boletus.
Length 7 - 10 mm.
May - September
             female    

A black abdomen with two yellow spots. Bright wings with a vague spot. Pipiza hoverflies have a flat face.

As you can see from the photos, there are two spots on the abdomen. Sometimes they miss those spots. (Often in males)
I often see them on leaves. But they also visit flowers.
It is very similar to Pipiza bimaculata.

Length: 6 - 10 mm.
April - September

The larvae  feed on aphids.

Heringia is a family, consisting of small black hoverflies. Females of this family are hard to identify. But the males are also not easy to indentify from a photo.
I cann't say wich Heringia spec it is. It even is not quite sure that it is an Heringia..

You see the most species oft on the leaves.

Length: 5 - 8 mm.
The larvae  feed on aphids.

   Photo 11-7-2010

male

female

Melanogaster hirtella  Family Melanogaster

As you see a very small black hoverfly.
On this photo on the flower of a Welsh poppy (Meconopsis cambrica). 
The Melanogaster hirtella is (just like the Cheilosia albitarsis) a real buttercup species.
Often in meadows near water. The eggs are attached under leaves of plants near the water. The larvae live along the waterfront. They overwinter as larvae.

 Length: 6 - 8 mm.
April - July.

Onion fly, Lesser Bulb Fly (Eumerus tuberculatus)  Family Eumerus

Also a small hoverfly. It is blackish-green with white markings on the abdomen

It has a "lump" by an extension at the beginning of the thigh. See detail photo.

The larvae feed on bulbs of onions, iris, narcissus or  hyacinths

Length: 5 - 6 mm.
April - September.