Who’s That Hoverfly? – Summer/Autumn 2013

This is the first installment of Who’s That Hoverfly?, a blog showcasing the hoverflies that I have found and managed (mostly!) to identify this year. Hoverflies are stunning insects and arguably the most popular group of flies. Some are present throughout the summer and autumn and a few can be seen throughout the year. Some are distinctive and straightforward to identify whereas others not so and need close scrutiny under a microscope! Hopefully you will find the notes on identification useful! Here goes…!

Episyrphus balteatus

A very common and familar hoverfly and one of the few with common name. Known as the Marmalade Fly (Episyrphus balteatus) it has very distinctive body markings. It can number abundantly particuarly with influxes of migrants.

Sphaerophoria scripta male

This species is Sphaerophoria scripta. The individual above is a male, told by the fact that the wings are shorter than the length of the abdomen. This is also the feature for easily identifying it and seperating it from other similar species. The female (below) is slighty different in appearance;

Sphaerophoria scripta female

S. scripta is one of the most common hoverflies in and around open grassland.

Syrphus vitripennis

This is Syrphus vitripennis. There are similar species. A good feature to note is that the hind femur is yellow towards the end whereas the upper part is black. (A similar species S. ribesii has an entirely yellow hind femur). A common and widespread species.

Platycheirus scutatus male

This is Platycheirus scutatus. Now there are many Platycheirus species and many with this basic pattern of yellow spots. It’s a male so I was able to take a closer look under the microscope at the front feet as the different species have subtle differences in shape, colour and arrangement of hairs.

Syritta pipiens 1

A small slender fly with basic markings, this is Syritta pipiens. A distinctive feature is the greatly swollen hind femur (below);

Syritta pipiens 2

S. pipiens is a widespread and abundant hoverfly.

Volucella inanis

A blurry photo but this is an easily recogniseable species – Volucella inanis. A large wasp mimic that has been gradually extending its range northwards. Note the body markings and the dusky wings.

The tribe Eristalini have a distinctive deep loop in the one of the wing veins (Radial vein 4+5).

Eristalini wing

A helpful feature as this deep loop points us straight to this tribe. The remaining hoverflies all belong to this genus and all have a deep loop in this vein.

Eristalis pertinax

This is Eristalis pertinax. There are species with similar body markings so the features giving this one away are that the tarsi of the front and middle legs are pale coloured. E pertinax is a common and widespread species.

Eristalis arbustorum 1

This is Eristalis arbustorum. A very variable species in appearance and it can be confused with others. Markings can range from as above to all black like this female below;

Eristalis arbustorum 2

Below is possibly E. arbustorum or a very similar species E. interruptus;

Possible Eristalis interruptus

E. interruptus has a more developed black facial stripe and some small differences in the wing that need close attention. I’m not sure however as I wasn’t able to catch it and only got this photo! Both these similar species are common.

Myathropa florea

This brightly coloured fly is Myathropa florea. Note the dense yellow hairs on the body and the greyish patches on the thorax which almost make out what looks like a face! A widespread species in Britain.

Criorhina ranunculi 1

Criorhina ranunculi 2

This furry bee mimic is Eristalis intricarius. The body colouring can very greatly. Note however the white bands on the legs, a helpful feature if confused with similar species. A widespread species but often low in numbers.

Helophilus pendulus

This attractive species is Helophilus pendulus. There are other Helophilus species which are very similar. At least half of the hind tibia in H. pendulus is pale. H pendulus is a common and widespread species. Below is one of those similar species;

H

This is Helophilus hybridus. The most reliable way to distinguish the species is is that only the basal third of the hind tibia is pale (see photo below).

Helophilus hybridus 2

H. hybridus is a more local species throughout Britain.

That’s all for this year. Hope you enjoyed it and look forward to looking out for these lovely insects next year.

All photos – Ashley Watson.

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