Thread subject: Diptera.info :: Giant Robber fly from Brazil

Posted by bonitin on 05-08-2010 21:24
#1

Hello,:)
I said giant because it had at least a size of 3cm or even bigger. I really thought it was a huge bumble bee but then saw its prey! I met it in the evening in a dense rain forest area in the region of Paraty-Brazil on the 2nd Febr. this year. Any help very much appreciated!:)
img704.imageshack.us/img704/1808/6thfebr2010016.jpg
img338.imageshack.us/img338/7033/6thfebr2010018large.jpg
Strange was that it had some little flies on its legs and even on the unfortunate prey, they obviously didn't fear the giant killer..
img709.imageshack.us/img709/8898/6thfebr2010020crop.jpg

Posted by Mark-uk on 05-08-2010 21:54
#2

And you didn't collect it? Criminal!!!

Posted by bonitin on 05-08-2010 22:05
#3

Sorry Mark! :| But I don't collect any bugs only take pictures. I cannot kill!

Posted by ChrisR on 05-08-2010 22:15
#4

Looks very similar to the ones I have here :)

Posted by Eric Fisher on 05-08-2010 22:21
#5

I agree with Chris: looks to be Mallophora tibialis.

Posted by jorgemotalmeida on 05-08-2010 22:26
#6

LOL Mark-uk. :)

Posted by ChrisR on 05-08-2010 22:35
#7

Eric Fisher wrote:
I agree with Chris: looks to be Mallophora tibialis.

It was my lucky guess - I only know one - and you told me that ;)

Edited by ChrisR on 05-08-2010 22:37

Posted by bonitin on 05-08-2010 23:04
#8

Thanks Chris and also Eric for the confirmation! :) That must be the one! But don't you think flies look more attractive in nature than pinned down? :|

Posted by Mark-uk on 05-08-2010 23:07
#9

I have to say pinned :P


Posted by ChrisR on 05-08-2010 23:53
#10

bonitin wrote:
Thanks Chris and also Eric for the confirmation! :) That must be the one! But don't you think flies look more attractive in nature than pinned down? :|

They look nicer in photos but it depends where you want to go after that. If you are happy with a great photo of an interesting fly then it is cool. But as soon as you want to know the name then you either need to take a specimen OR you rely on the expertise of people who have taken specimens and put in a lot of study with them ;)

Posted by bonitin on 06-08-2010 00:43
#11

Yes, sure Chris that makes sense! I realise, though many species often don't need a specimen to id. as they have no look-a-likes..:)

Posted by Eric Fisher on 06-08-2010 05:56
#12

ChrisR wrote:
It was my lucky guess - I only know one - and you told me that

Not luck -- you are just an excellent student!

bonitin wrote:
many species often don't need a specimen to id. as they have no look-a-likes..

Not true in this case: several of robber flies (in two genera of distinct subfamilies) mimic the Eulaema bees which are the models here -- and many Eulaemas mimic each other, so it all gets pretty complicated. Specimens are often essential.

Edited by Eric Fisher on 06-08-2010 05:59

Posted by jorgemotalmeida on 06-08-2010 07:58
#13

There are several asilids that mimics well the bees and bumblebees.
But one the best mimics of the bumblbees belongs to an Oestrid: Portschinskia loewi . :)
http://www.dipter...ad_id=8124

Posted by ChrisR on 06-08-2010 09:01
#14

Also, my point was that experts make it look easy - show a nice photo and you get a name for it. But to get to the stage where you know the name there have been hundreds of people have had to collect specimens, work tirelessly for decades working out the taxonomy and then (and only then) if they have *real* familiarity with a group they might be able to see something in the photo that points to what the species is ... but often it is just an educated guess based on experience - with a specimen then they would really know.

This is especially true in the neotropics where mimicry complexes are very common and bio-diverse. We can say that it looks like Mallophora tibialis but perhaps if we could see the genitalia or the bristles more closely then we'd see that it was an undescribed species or even a new genus. :)

So, absolutely, photos are a great way to document (not record) the biodiversity of the world ... but only rarely can you actually say for sure that the photograph shows a specific species - even in Europe. The best way is to take plenty of photos from all angles and then also take specimens to bring back and give to the experts. Then you really will know what is in the photo ;)

Edited by ChrisR on 06-08-2010 09:02

Posted by conopid on 06-08-2010 09:30
#15

And just look at all those marvellous little Milichiidae swarming all over the Asilid - would love to know what they are too!

Posted by bonitin on 06-08-2010 11:39
#16

OK! Thanks Chris, Eric and Jorge! I understood!:) You made your point clear!
I've added the robberfly to the gallery.

Ah thank you Nigel for giving attention to the cute little flies, at least I know their family now, they look a bit like fruitflies to me..

Myriam:)

Posted by Eric Fisher on 06-08-2010 15:47
#17

Nigel,

I wondered if those little guys were milichiids (the most common 'visitors' to asilid prey) but they look a bit different (??). So much to learn...

Eric

Posted by ibrake on 03-09-2010 10:27
#18

It is hard to tell, but the little flies could be Milichiella lacteipennis, a common milichiid species known and quite often observed as kleptoparasite. See http://milichiida...cteipennis.

Irina