The Hoverfly Thread (3 Viewers)

[Ficedula]

Hello again,

Another one from the canal, regrettably the only image I got so no views of the hind femur. Could this be a good one for Syrphus ribesii though?

Regards,
Andrew.

Syrphus sp

 

[Andrew]

miles out! Syritta pipiens

Thank Dave. I need to take better images then to give me a fair chance!

Syrphus sp

Pity it can not be taken further but thanks. One to try for again.

 

[Ficedula]

Thank Dave. I need to take better images then to give me a fair chance!

no, what you need to do is take specimens and key them, your failure to recognise the very common Syritta pipiens, which you must have seen before, is a classic example of the impossibility of adequately learning insects (apart from the really obvious) without carefully keying specimens, it is not you, everyone who does not take specimens is the same. Simply because of the size of most insects, even with excellent camera equipment you are in the same situation as a short-sighted birdwatcher who does not own any optics trying to name distant birds! if you are already a very experienced birder you can do a lot on call and jizz, but no beginner will ever become a good birder if they never buy optics. Entomology no different, I only recognise your photos because I have examined hundreds of specimens that I had observed in the field. At the very least you need net and handlens and take the key into the field (many hoverflies can be keyed alive), but ideally you need a microscope.

 

[Andrew]

no, what you need to do is take specimens and key them, your failure to recognise the very common Syritta pipiens, which you must have seen before, is a classic example of the impossibility of adequately learning insects (apart from the really obvious) without carefully keying specimens, it is not you, everyone who does not take specimens is the same. Simply because of the size of most insects, even with excellent camera equipment you are in the same situation as a short-sighted birdwatcher who does not own any optics trying to name distant birds! if you are already a very experienced birder you can do a lot on call and jizz, but no beginner will ever become a good birder if they never buy optics. Entomology no different, I only recognise your photos because I have examined hundreds of specimens that I had observed in the field. At the very least you need net and handlens and take the key into the field (many hoverflies can be keyed alive), but ideally you need a microscope.

Evening,

I already own a net and am willing to capture specimens but have yet to obtain a microscope which is something I can not do for at least a month yet. I take on board your advice that some specimens can be keyed in the field which is encouraging. The problem is in an attempt to year list everything in Devon this year I am limited to what I can carry so I think I shall need to have at least one day a week where I focus on hoverflies and take just the Stubbs & Falk, a net, lens and tubes with me. This focus should probably be good for at least a couple of new species a week I think, especially the darker ones which I usually back off from. Collateral catches on such days could include moths, diptera, etc.

Thanks for the advice.

Regards,
Andrew.

 

[Matt Prince]

Andrew,

Bizarrely a couple of clear plastic bags are proving quite useful in the field, gives the opportunity to get a good x10 lens view (still not sure that x20 brings much to the party but thats another thread...) without killing the subject (though I've come close from sheer frustration, and its still not much use for the little jobs when wing venation is nigh on impossible).

All bets are off when looking for the dreaded squama of course...

Does anyone know of any good hoverfly workshops or field meetings - I'm Devon based, but I'd be surprised if there aren't people from many counties in a similar position. A good id workshop, including some time with a dissecting microscope, would be very useful for some of us that are just getting to grips with Stubbs & Falk.

Matt

 

[Matt Prince]

Does anyone know of any good hoverfly workshops or field meetings

Just had a internet trawl for this sort of thing, and noted that on the Hoverfly recording scheme Roger Morris was offering training courses for the winter 2011/2012 - looking for classes of 12 in "North-East, North-West, Devon/Cornwall, Wales and Cheshire/Lancashire." with venue to be provided by candidates and costs no more than £30 for a full class, all microscopes and materials provided.

I think I could sort a venue in or around Exeter, anyone else up for this on the above basis?

Regards,
Matt

 

[Andrew]

Evening mate,

I just found some nifty 'craft jars' that might allow me to place live specimens and examine them under a lens but I shall pack some plastic bags too.

http://www.dipteristsforum.org.uk/t1099-Training-events.html
Know anyone qualified enough or willing to step up to the plate for Devon? I would certainly attend both options if someone set it up.

Cheers,
Andrew.

 

[Andrew]

Did not see your follow up post Matt. I would definitely attend that especially if it was in Exeter and I am sure Nigel would too.

If well advertised, I think a few others may turn up. DWT magazine?

Cheers,
Andrew.

 

[Matt Prince]

Well that's a 1/4 of the students required, 1/3 if I can twist my other halfs arm a little. I'll see if I can get in touch with Roger Morris and maybe start a seperate thread, but I'll post back here when I have anything of wider interest (on the grounds that others might want to consider a workshop and it is relevant to hoverfly id).

having seen your interim post - I'd hope that any course at least touches upon preservation of specimens. Not big on the killing aspect - but s'long as its leads to useful records - its better than no data, or worse, invalid data.

Anyway - how about some more hoverfly pictures - myathropa florea would be nice, even I can identify that from a half decent picture!

 

[Ficedula]

By far the best way to det flies alive is to hold them in your fingers, then you can manoeuvre them any direction, do not have to look through glass/plastic, and sometimes they even sit still! start with large Eristalis before you try more delicate species. Just hold 2-3 legs between thumb and forefinger in such a way that they can perch naturally. Other fly families are more problematical as some will shed legs, but hoverflies do not.

 

[Matt Prince]

Thanks for that tip Dave, I'll try it, as seeing fine dusting on the frons through plastic is problematic at best. I'm assuming your technique is to net them, extract by hand, then key them with a x10 hand lens.

Ill probably keep the plastic bag for now though, as I find it useful for checking out the epigyne of female spiders (like a low tech version of Roberts spy-pot), and occasionally hovers trapped into a small portion of the bag, sit still long enough to check for things like fine leg detail.

Cheers,
Matt

 

[Matt Prince]

As mentioned above I've started a thread for anyone interested in a hoverfly workshop in the Devon area (or SW for that matter)

here

Despite the high winds on Sunday, good numbers of V. Bombylans var. plumata on Hemlock Water Dropwort around Dawlish Warren, outnumbering the 'normal' form.

 

[Andrew]

Morning,

I have heeded the words of advice and have enjoyed keying my own hoverflies and managed no less than eight in one visit at Meshaw Moor recently.

However, I need to ask of one that I photographed way back on the 7th May. I had this one down as Sericomyia lappona but I am now not sure as it is not common down here and the legs do not seem entirely orange. It does not look right to me for S. silentis which I have recently keyed. It was photographed at Haldon Forest.

Can anyone advise on this one?

Regards,
Andrew.

 

[Ficedula]

Sericomyia lappona

correct

 

[Andrew]

correct

Fantastic, thanks Dave. It has been on my mind as I have looked in places for one without realising I had already seen one!

Regards,
Andrew.

 

[Andrew]

Hello,

Attached are two images of a hoverfly seen at Witheridge Moor (Devon) a week or two ago within a culm grassland habitat. I suspect this is Pipiza austriaca and you can see the swollen femur in one of the images.

Regards,
Andrew.

 

[Odonate]

Hi all

Can I just check with the experts that this is Volucella bombylans and not Eristalis intricaria? I don't have access to a Hoverfly guide and I have had to interpret the wing venation difference from various websites.

Thanks

O

 

[Matt Prince]

Hi all

Can I just check with the experts that this is Volucella bombylans and not Eristalis intricaria? I don't have access to a Hoverfly guide and I have had to interpret the wing venation difference from various websites.

Thanks

O

I'm not an expert, but I can rule out Eristalis - that genus is easy to identify with its whopping dipped vein, look aat the huge dip in this wing diagram - above the 'r4+5' in the following image:-

Eristalis Wing veins

 

[Matt Prince]

Your fly has a deep v near the end of the wing - V for Volucella..

(In this case volucella bombylans, variation plumata because of the white tail)

Cheers,
Matt

 

[Odonate]

Thanks, I had understood correctly it seems

O