Nature in your local patch
OPAL West Midlands: Nature in your local patch
Female Red Mason Bee (Osmia rufa) constructing a nest (Photograph © Nicolas J. Vereecken).
A colour-ringed Blue Tit (Cyanistes caeruleus) (Photograph © Katie Glover)
Early Summer Hoverflies
These species are are all common in May through to August and all three species belong to the Eristalini tribe of Hoverflies. We’ll start with an easy question: Why is it not a bee? This is not as daft a question as it might seem as many species in this group, especially those in the genus Eristalis, look like honey bee workers. Others resemble bumble bees. The answer to the question is that they have two wings not four (organised in two pairs) like bees and wasps. The thing that makes these species members of the Eristalini is the presence of a looped vein in the wing (see picture above) - they all have this characteristic. If you see this and it looks a bit like a honey bee then look closely at its scutellum (the small triangular bit in between the wings) (see below). If it is not black but a brown/yellow colour then it is an Eristalis hoverfly (or drone fly).
Identification guide No. 1: Easy summer hoverflies (Eristalini)
We thought it might be useful to create a few limited identification guides to point out species that are easily recognizable and around at certain times of the year. We are starting here with three easily recognizable early summer hoverflies (Eristalis tenax, Myathropa floralis and Merodon equistris).
We thought it might be useful to create a few limited identification guides to point out species that are easily recognizable and around at certain times of the year. We are starting here with three easily recognizable early summer hoverflies (Eristalis tenax, Myathropa floralis and Merodon equistris).
The next thing to do is look at its head. The most common species, Eristalis tenax, has a thick black band on the front of its head and two hairy bands on each eye (and I mean the bands are made of hairs) - see picture on the next page. There are nine species in the genus but this one is easy to spot!
Another easy one is Myathropa florea. It looks similar to Eristalis but is very brightly coloured. Look for the distinctive pattern on the thorax (the bit just down from the head), which looks like a black blob with two bisecting yellow bands. To my eyes it resembles a caricatured skull! Unmissable! This is a species often found on umbellifers as an adult. The larvae live in water filled crevices in wood (rot holes in trees). The last one for today is the bumble bee mimic, Merodon equistris. The species comes in a variety of colour forms (black with a red tail - mimicking Bombus lapidarius; black and yellow with a white tail - like e.g. B. lucorum; and tawny - like B. pascuorum). It looks like a bumble bee and always has black legs and the looped vein on the wing. The species lays its eggs next to plants with bulbs. It is a pest of bulb growers in the Netherlands, but you have to say it is pretty nice. Other bumble bee mimics (and there are several) have either yellow on the legs (i.e. tibia) or no looped vein.
If you are interested, I think that these are an easy group to work with, there is a fantastic key available from the British Entomological and Natural History Society:
Stubbs, A.E. and Faulk, S.J. 2002. British Hoverflies: An illustrated identification guide. 2nd edition.
This is how all keys should work - it is brilliant. There is also an active recording scheme to get involved with:
http://www.hoverfly.org.uk/
Click here to download an PDF file of this guide.
All photographs are by Jon Sadler.
Stubbs, A.E. and Faulk, S.J. 2002. British Hoverflies: An illustrated identification guide. 2nd edition.
This is how all keys should work - it is brilliant. There is also an active recording scheme to get involved with:
http://www.hoverfly.org.uk/
Click here to download an PDF file of this guide.
All photographs are by Jon Sadler.
