Hoverfly for ID Please

[PeterD]

Some of the hoverflies I photographed yesterday. I have been unable to fully ID these although a couple look familiar.

#1


#2


#3


#4


Thanks

[JRsbugs]

#1 female Episyrphus balteatus
#2 male Platycheirus, could be P. albimanus.
#3 female Eupeodes luniger
#4 male Epistrophe elegans

Janet

[PeterD]

Originally Posted by JRsbugs

#1 female Episyrphus balteatus
#2 male Platycheirus, could be P. albimanus.
#3 female Eupeodes luniger
#4 male Epistrophe elegans

Janet

Thanks Janet. The only one of these I have seen before is #1. I think this is because I only started into these last June and maybe missed them that way.

[Geoff F]

I'm not sure how many species of hoverflies there are in the UK, Peter, but it is a lot. And many species are difficult to separate.

Take no. 2 for example; where Janet said P. albimanus, a very common spring hoverfly. Looking at what is visible of the abdomen spots, I would agree that is the most likely, but to be absolutely certain we would need a good view of the front leg. The males, like your specimen, have a widened area on the tibia/tarsus which is unlike any similar species.

Hoverflies are an interesting, easy to find and photograph family; at least until you get the desire to find some of the rarer species!

If you really want to learn everything about them, I would recommend reading British Hoverflies by Alan Stubbs. An excellent read, but not exactly cheap though.

[PeterD]

Originally Posted by Geoff F

I'm not sure how many species of hoverflies there are in the UK, Peter, but it is a lot. And many species are difficult to separate.

Take no. 2 for example; where Janet said P. albimanus, a very common spring hoverfly. Looking at what is visible of the abdomen spots, I would agree that is the most likely, but to be absolutely certain we would need a good view of the front leg. The males, like your specimen, have a widened area on the tibia/tarsus which is unlike any similar species.

Hoverflies are an interesting, easy to find and photograph family; at least until you get the desire to find some of the rarer species!

If you really want to learn everything about them, I would recommend reading British Hoverflies by Alan Stubbs. An excellent read, but not exactly cheap though.

Thank you for your reply and advice Geoff. I have looked at all the photos I had taken of #2 and in none is there a clear shot of the leg which I can zoom into. I have decided to accept Platycheirus sp as I think it would be difficult to convince anyone of the species.

I shall look up the Stubbs book with a view to adding it to my reference material. It could prove useful for both ID and info to add to my website. I suppose my problem is that I am not specialising and the topics I am covering makes for one heck of a lot of ground to cover. I have learnt a lot in this past year since creating the site but there is a massive mountain yet to climb.

[PeterD]

Geoff,
I think this clinches #2. Taken today.

http://www.imageinuk.com/True-Flies-...46_HHX6Q-L.jpg

[JRsbugs]

I think you will find other male species have swollen front tarsi too.

The spots of the male P. albimanus age to a gold colour, so this is probably newly emerged. I guess it's possible others might start with paler spots too.

Diptera.info - Photo Albums: Syrphidae

[PeterD]

Originally Posted by JRsbugs

I think you will find other male species have swollen front tarsi too.

The spots of the male P. albimanus age to a gold colour, so this is probably newly emerged. I guess it's possible others might start with paler spots too.

Diptera.info - Photo Albums: Syrphidae

Thanks for your reply Janet.
Guess we are back where we started on this one, Platycheirus sp

[JRsbugs]

Peter, you need to go through a key, and often need to see both front and mid tibia and femora.

I have tried to key yours out and the one I have come to didn't need the femora, and if I did it correctly I got Platycheirus discimanus.

You are in the right area, it isn't well recorded, and I could be wrong but everything I have looked at according to the key seems to fit.

I haven't tackled mine yet from last year, grooooan nightmare,

[Geoff F]

According to Mr. Stubbs, that is definitely P. albimanus. P. discimanus, besides being rather uncommon, has an almost round expansion at the start of the tarsus; while P. albimanus has a rather one sided expansion on the end of the tibia plus a tapering expansion on the tarsus.

Peter's excellent photo exactly matches Stubbs's drawings.

The expanded section of P. albimanus is rather similar to P. peltatus and P. scutatus, both of which have rather bright yellow spots.

The other silver spotted species which can be mistaken for P. albimanus is P. ambiguus but this lacks any expansion. As does the Melanstoma species which can sometimes enter the silver/bronze spot confusion.

But remember we are only talking about males here.

When you get the Stubbs book, Peter, you will find these diagrams on page 422. I suppose if you consider that this book has around 450 pages, the price doesn't seem quite so bad!