Hover fly ID please

Janenat · #1 (**permalink**) 12-08-2010, 11:07 AM

Hello

2 for ID please

Many thanks

Jane

JRsbugs · #2 (**permalink**) 12-08-2010, 01:44 PM

The pics are a little too far off, but by general gist #1 female Eristalis tenax, #2 Syrphus ribesii female.

Janet

Janenat · #3 (**permalink**) 12-08-2010, 02:00 PM

Thank you

Jane

Jason Green · #4 (**permalink**) 12-08-2010, 02:25 PM

Afternoon Jane,

I agree with the first being Eristalis, but not decided between tenax or pertinax ( the eyes look equally covered in hair, and the hind tibia shows two shades - both in-line with pertinax in my opinion).

You need a view of the hind femora/close-up of the eyes to get past Syrphus sp. for the second, which unfortunately doesn't show - the dorsal markings and colouration are shared by all three UK Syrphus spp. so can't be used in seperation.

Take care,

Jason

JRsbugs · #5 (**permalink**) 12-08-2010, 02:28 PM

Quote:

Originally Posted by Jason Green

Afternoon Jane,

You need a view of the hind femora/close-up of the eyes to get past Syrphus sp. for the second, which unfortunately doesn't show - the dorsal markings and colouration are shared by all three UK Syrphus spp. so can't be used in seperation.

Take care,

Jason

Yes, but I still say on gist it's S. ribesii. The abdomen marks are typical.

Jason Green · #6 (**permalink**) 12-08-2010, 02:43 PM

The abdominal colouration is too variable between all three, and to the very best of my knowledge isn't used in species-level identification for the Syrphus genus.

There is no need to go to species level here since we can't see the feature needed to get further reliably, but at least we agree on Genus!

JRsbugs · #7 (**permalink**) 12-08-2010, 02:52 PM

Yes but, Jason, going on gist isn't a 100% ID. I somehow don't think Jane is going to submit it for records, so it doesn't matter a great deal and she probably would like to put a possible name to it for her own records. In that case it matters not a tot.

Please correct me Jane if I'm wrong on that point!

Janenat · #8 (**permalink**) 12-08-2010, 03:48 PM

attached 2 more pics not sure if they will help, I've only just started on the ID'ing hover flies so genus and a possible is fine by me so I can start to see the different genus, appreciate all the help
Jane

JRsbugs · #9 (**permalink**) 12-08-2010, 03:57 PM

Your last pic shows it to be a male, or so it looks! The marks are still quite shallow though. On males the hind femora is either 2/3 black or black just at the base. The frons looks dark, which is just visible in the first pic too.

Entomology Collection > Syrphus ribesii