Wednesday 28 April 2010

Comparison

Smaller hoverflies have been a bit scarce this year, so it was interesting to get two very illustrative shots within minutes of each other.

These are both males (the two large eyes meet in the middle, divided by a very narrow margin), and they seem very similar at first glance. Abdominal patterns are obscured by the wings, so we can't use those as confirmation of species, but we can easily get to family for both. (Both are roughly the same size: about 12mm long)

For the first one, we have a delicate specimen with a relatively longer abdomen, dark scutellum (the D-shaped bit between the wings) and smaller feet. The yellow fascia ('face') is also small and delicate. Melanostoma fits well for family and scalare would be a good bet for species.


The second specimen is much more robust, and has a more pronounced fascia and much larger front 'feet'. The front feet alone point to Platycheirus sp., and I'd hazard a guess at Platycheirus scutatus based on location and overall feel, but that isn't a positive id.

Here's a shot of one of the larger front feet, known as 'inflated tarsi' in the references.


2 comments:

Gill said...

Nice comparison page - thanks Stuart. It's great to see what "inflated tarsi" actually look like.

Yoke, said...

Thanks, Stewart,