Terrelia serratulae male. What are the blue bits for?

[Andestine]

Hello,

I found this handsome fly on a thistle in my garden last summer. I know what it is, but have been unable to find a name or precise function for the blue bits, except that it's been suggested that it is probably to do with mating.

I'd be very grateful if someone could satisfy my curiosity. Photos from other angles available if needed.

Cheers,

Andestine

[Lindsay-c]

pheromone producing glands ? Would make sense if it's to do with mating...

And very nice picture

[JRsbugs]

I have found an answer from Paul Beuk on the nhm site, he is the owner of diptera.info. If you post there you might attract the attention of an expert on Tephritidae, his user name is Nosferatumyia. Assuming it is Tephritidae as it has no markings on the wings but the rest looks like it!

Janet

[Fauna]

There is an interesting photo on Flickr of a male wiggling his bits to entice a female.

If you copy and paste this link it should take you staraight to it. (did not realise links activated automatically??)

Terellia cf. serratulae (cortejamento) | Flickr - Photo Sharing!

[theresa dockery]

Copied & pasted from: http://www.sel.barc.usda.gov/diptera.../tephbehv.htm.

"Males of most species of Tephritidae that have been studied secrete some type of sex-attractant chemical, either by inflating the lateral abdominal membranes or by extruding an anal pouch (Pritchard 1967, Headrick & Goeden 1994). They disperse these pheromones by wing fanning, which also produces sounds of possible significance in courtship (Sivinski & Webb 1985, Mankin et al. 1996)."

It goes on to mention other fruit flies which form leks and apparently males of some species offer 'nuptial' food gifts to females. Some very interesting info on that link...if slightly 'wall of text'.

Originally Posted by Fauna

There is an interesting photo on Flickr of a male wiggling his bits to entice a female

That article could have used some pretty photos like this to spice it up

[Andestine]

Originally Posted by Lindsay-c

pheromone producing glands ? Would make sense if it's to do with mating..

Absolutely . One of my first guesses too.

And very nice picture

Thank you I started to teach myself DSLR photography last March and am now obsessed with it. I love all flies, but this one is my favourite. It was taken in natural light only. He was very small. His body looked like porcelain, and he posed very nicely for ages. I had never seen one like it before and he was utterly entrancing

Leaving thistles to grow high in my garden is what drew him there, I believe

Cheers,

Andestine

[Andestine]

Originally Posted by JRsbugs

I have found an answer from Paul Beuk on the nhm site, he is the owner of diptera.info. If you post there you might attract the attention of an expert on Tephritidae, his user name is Nosferatumyia. Assuming it is Tephritidae as it has no markings on the wings but the rest looks like it!

Janet

Hello Janet,

Yes, that was me under another name warming up with some ID's before returning to WAB ( a very nice, well-moderated nascent ID forum that one is )

As you can see, I had found a very good photo-match on Diptera.info, and Paul confirmed it, but then went on to say:

ID is correct. I do not know the name of the sacks but they most definitely play a role in mating / mate 'selection'. Whether it is for physical or chemical signalling I cannot say off-hand.

Paul

So I said I'd continue to search but found nothing, so I decided to come here first before posting to Diptera.info. And there, you see, Theresa found just what I was looking for, so I need to search no further

My only regret now is that I'll have no excuse to talk to the wonderfully named Nosferatumyia (Love the film).

Thanks so much for all the help,

Cheers,

Andestine

[Andestine]

Originally Posted by theresa dockery

Copied & pasted from: http://www.sel.barc.usda.gov/diptera.../tephbehv.htm.

"Males of most species of Tephritidae that have been studied secrete some type of sex-attractant chemical, either by inflating the lateral abdominal membranes or by extruding an anal pouch (Pritchard 1967, Headrick & Goeden 1994). They disperse these pheromones by wing fanning, which also produces sounds of possible significance in courtship (Sivinski & Webb 1985, Mankin et al. 1996)."

Wow Theresa. Brilliant! First prize

When I tried to follow the link this morning I kept on getting a 404. Is there any other way in?

Your excerpt mentions inflation or extrusion. Now I watched that fly for a good two hours and took hundreds of photos. There wasn't a female in sight yet he never once let his blue bits down. Maybe he was getting pretty desperate by then

If you take a look at the two other photos I sent, you can see that his blue bits look pretty permanent, but could be inflated or extruded, of course. Now what I'm wondering is if anyone has taken a picture of the male of this species with the blue bits in non-display mode? What do you think?

It goes on to mention other fruit flies which form leks and apparently males of some species offer 'nuptial' food gifts to females. Some very interesting info on that link...if slightly 'wall of text'.

I know what you mean. So many scientific texts about invertebrates are like that. It's one of the many reasons I like WAB so much, because it blends good science with fun and lovely diversions

I was recently chatting with a friend about a fascinating nugget of research I'd discovered about Nursery Web Spiders and nuptial gifts, and I thought that only spiders offered these until you mentioned that some fruit flies do it too.

Also many thanks for introducing me to the concept of a 'lek'. I had to look it up, of course I'm very new to learning about invertebrate behaviour and find it completely intriguing. Looking down a macro lens for hours every day certainly helps you see the most extraordinary things going on in a world you never even noticed before

That article could have used some pretty photos like this to spice it up

Indeed.

Like you, I also know how to write dry, scientific texts when its required. But I do wish it didn't always need to be quite so boring and incomprehensible to just about everyone else. I support the Oliver Sacks school of scientific writing myself

I do accept that scientific papers have to be couched in language like that, but science can be so exciting, and I just wish there was more good writing out there for everyone to enjoy

I read Rossco's book 'Extraordinary Animals' while I was away. Now there's an example of someone who knows what he's talking about yet also knows how to make it fascinating and fun to read . On returning I was sad to see that he hasn't posted here for a couple of months now...and his blog's a bloomin' good read too.

But I digress....as usual

Thanks again Theresa (so nice to be back here again amongst other enquiring minds )

Cheers,

Andestine

[Andestine]

Originally Posted by Fauna

There is an interesting photo on Flickr of a male wiggling his bits to entice a female.

If you copy and paste this link it should take you staraight to it. (did not realise links activated automatically??)

Terellia cf. serratulae (cortejamento) | Flickr - Photo Sharing!

Thank you Christian! That's a perfect picture of how it displays its blue bits

I was amused to find that although I don't speak that language, it wasn't too hard to understand the caption :

É possível observar uma protuberância no abdómen do macho, provavelmente um "saco" a partir do qual são libertadas feromonas com o objectivo de atrair a fêmea.

I'm adding a couple more of the photos that I posted to the NHM site of the protruberances here just for fun I'm not an expert on flies, but haven't seen anything like that on any other species I've seen so far. They're quite something.








Sadly, I watched my fly for hours that day, and he was all alone, so I had no chance to see his display. But I'll be growing thistles again next year and your wonderful link has inspired me to try to photograph the mating ritual

Cheers,

Andestine

[theresa dockery]

Try this: Fruit Fly (Diptera: Tephritidae) Behavior

It doesn't say how long they inflate/extrude for - maybe it is more or less permanent?

Fruit flies seem to be quite popular lab subjects so I'm surprised there aren't more webpages or info on their anatomy & lifestyles (with photos to illustrate these) - I'm thinking along the lines of tristanba's excellent 'British Bugs' website http://www.xexexexexexexexexexexe.org.uk/...you will have to google that one I'm afraid - WAB seems to find Hemiptera offensive

Maybe it's just a matter of time until someone does the same for Dipterans (there are so many, each family would need to have their own website I imagine!).

Originally Posted by Andestine

But I do wish it didn't always need to be quite so boring and incomprehensible to just about everyone else.

One of my professors had a saying 'A good scientist can make his work understandable to all' - I think a wee bit of humour, colourful photographs & avoiding excessive pedantry can make science accessible to everyone without 'dumbing down'.

I'm a member of the PSG (Phasmid Study Group) and we get a twice yearly copy of the journal 'Phasmid Studies' - most of the articles are very easy to read & enjoyable, but there are sometimes a few in which terminology is taken so far as to be incomprehensible (every single word requires a search on google - as the words are too specific to be found in the dictionary).

I may be quite cheeky to say this, but I've often thought that a few of my university professors need to get out of their 'ivory towers' more!

Originally Posted by Andestine

I read Rossco's book 'Extraordinary Animals' while I was away. Now there's an example of someone who knows what he's talking about yet also knows how to make it fascinating and fun to read . On returning I was sad to see that he hasn't posted here for a couple of months now...and his blog's a bloomin' good read too.

Oh, give me the link for that! I'm always on the lookout for interesting nature blogs. Shame my 'blogger' account only allows me to 'befriend' people who also have 'blogger/blogspot' accounts - I think 'wordpress' has similar incompatibility issues