Gallery Links
Users Online
· Guests Online: 2

· Members Online: 0

· Total Members: 4,945
· Newest Member: millenin
Forum Threads
Newest Threads
· Unknown Stratiomyida...
· Milichiidae?->Chloro...
· Heleomyzidae ?
· Ceratopogonidae (Ton...
· Bibionidae: Bibio re...
Hottest Threads
No Threads created
Theme Switcher
Switch to:
Last Seen Users
· Marcello15 weeks
· Paul Beuk46 weeks
· JWV60 weeks
· Nosferatumyia72 weeks
· daveb2172 weeks
· guplox72 weeks
· ESant72 weeks
· Jan Maca72 weeks
· libor72 weeks
· Reimund Ley72 weeks
Latest Photo Additions
View Thread
Diptera.info » Family forums » Asilidae Forum
Who is here? 1 guest(s)
 Print Thread
Robber Fly from Sussex chalk downs, England
Perseus
farm4.staticflickr.com/3724/9523353147_d71367b2de_b.jpg

The usual specimens we get are the Hornet Robber Flies, Asilus crabroniformis, so this one came as a surprise. Seen at the beginning of August 2013.

Location: http://www.glaucu...l2013.html
 
ChrisR
Could it just be a freshly emerged Asilus? Do you have more angles and can you give us an idea of their size, relative to the usual Asilus?
Manager of the UK Species Inventory in the Angela Marmont Centre for UK Biodiversity at the Natural History Museum, London.
 
http://tachinidae.org.uk
Perseus
Thanks for you suggestion. I had it automatically down as Asilus until I saw the picture. And even then I was not sure until somebody else came up with the query from their own observations. Asilus is regularly seen at both sites as this one. But definitely smaller by 20% this one.

It is the only photograph. Instant reactions of point and shoot as it only settled on a chalky path for a second. Lucky to get it in the frame at all.
Edited by Perseus on 17-08-2013 10:04
 
Perseus
www.glaucus.org.uk/HornetRobber577.jpg

One of the normal Asilus. They are great predators on butterflies. From local observations second aerial predator to the Southern Hawker. Hundreds of prey items in an acre at the moment.

I think this one shows the relative sizes.
Edited by Perseus on 17-08-2013 20:18
 
Perseus
Addenda: behaviour and location was identical to Asilus. So were dates. But dates are still behind this year. Not three weeks like before the warm spell, but about a week behind for the butterflies.
 
Fred Fly
Couldn't it be Machimus rusticus?
 
Perseus
Piet Nord wrote:
Couldn't it be Machimus rusticus?


Thanks for the suggestion. Cross reference: http://72.44.83.9...pid=189406

http://www.insect...mp;t=90850
Edited by Perseus on 18-08-2013 00:02
 
Quaedfliegh
I think it is M rusticus but i should see a lateral image.
Edited by Quaedfliegh on 19-08-2013 23:15
Greetings,

Reinoud

Field guide to the robber flies of the Netherlands and Belgium: https://www.jeugdbondsuitgeverij.nl/product/field-guide-to-the-robberflies-of-the-netherlands-and-belgium/

https://www.nev.nl/diptera/
 
Mariastraat 12
Perseus
https://www.facebook.com/photo.php?fbid=10201970770899524&set=gm.325800567555559&type=1&theater

Same location, same year, possibly the same species: https://www.facebook.com/photo.php?fbid=10201970770899524&set=gm.325800567555559&type=1&theater
 
Perseus
fbcdn-sphotos-b-a.akamaihd.net/hphotos-ak-prn2/1146638_10201970770899524_551157248_n.jpg
 
Perseus
The above picture (by Su Reed) was found in the same location several times, but this is the first photograph. I have only seen one.
 
Quaedfliegh
This last pictures is a female Tolmerus (Machimus) atricapillus (could also be T. micans but that species has never been recorded in the UK). In the Netherlands Tolmerus atricapillus is called the "Common robberfly", together with Dysmachus trigonus by far the most widespread asilid. In NL it is rarer on chalk grasslands in the south. Very numerous on sandy soils. Machimus rusticus, on the other hand is only found on chalk grasslands in NL.

I am pretty sure this is M rusticus but based on looks, location and shape of genitalia. In the UK there is a look alike, M arthriticus. This species has usually more red on tibia, more slender male genitalia and prefers a sandy soil. To be sure the underside of the front femora should be visible, if there is only hair it is rusticus, if there is a row of bristles too then M arthriticus.
Edited by Quaedfliegh on 21-08-2013 17:30
Greetings,

Reinoud

Field guide to the robber flies of the Netherlands and Belgium: https://www.jeugdbondsuitgeverij.nl/product/field-guide-to-the-robberflies-of-the-netherlands-and-belgium/

https://www.nev.nl/diptera/
 
Mariastraat 12
Perseus
Quaedfliegh wrote:
This last pictures is a female Tolmerus (Machimus) atricapillus (could also be T. micans but that species has never been recorded in the UK). In the Netherlands Tolmerus atricapillus is called the "Common robberfly", together with Dysmachus trigonus by far the most widespread asilid. In NL it is rarer on chalk grasslands in the south. Very numerous on sandy soils. Machimus rusticus, on the other hand is only found on chalk grasslands in NL.

I am pretty sure this is M rusticus but based on looks, location and shape of genitalia. In the UK there is a look alike, M arthriticus. This species has usually more red on tibia, more slender male genitalia and prefers a sandy soil. To be sure the underside of the front femora should be visible, if there is only hair it is rusticus, if there is a row of bristles too then M arthriticus.



Thanks for the last reply. I have independently IDed the last picture as Machimus atricapillus Unsure now after a break. Linked in picture to this discussion. The first one was assumed to be the same species. It might not be though?
Edited by Perseus on 02-12-2013 03:36
 
Quaedfliegh
No, last picture is not the same species as the one in the first picture. Asilidae might be a difficult lot but.... Last picture is Tolmerus (Machimus) atricapillus 99.9% : ) First picture is probably M. rusticus by default again.


Greetings,

Reinoud

Field guide to the robber flies of the Netherlands and Belgium: https://www.jeugdbondsuitgeverij.nl/product/field-guide-to-the-robberflies-of-the-netherlands-and-belgium/

https://www.nev.nl/diptera/
 
Mariastraat 12
Jump to Forum:
Similar Threads
Thread Forum Replies Last Post
Cambodia robber fly -> Philodicus sp. Asilidae Forum 3 13-06-2023 14:56
Robber fly species? Asilidae Forum 3 26-09-2021 14:51
Robber fly? Diptera (adults) 1 22-07-2020 21:55
Orange haired robber fly (Germany) ? Asilidae Forum 4 13-06-2020 12:51
Robber fly ? from Spain Asilidae Forum 1 01-06-2019 17:14
Date and time
11 July 2025 03:25
Login
Username

Password



Forgotten your password?
Request a new one here.
Temporary email?
Due to fact this site has functionality making use of your email address, any registration using a temporary email address will be rejected.

Paul
Donate
Please, help to make
Diptera.info
possible and enable
further improvements!
Latest Articles
Syrph the Net
Those who want to have access to the Syrph the Net database need to sign the
License Agreement -
Click to Download


Public files of Syrph the Net can be downloaded HERE

Last updated: 25.08.2011
Shoutbox
You must login to post a message.

17.08.23 15:23
Aneomochtherus

17.08.23 13:54
Tony, I HAD a blank in the file name. Sorry!

17.08.23 13:44
Tony, thanks! I tried it (see "Cylindromyia" Wink but don't see the image in the post.

17.08.23 11:37
pjt - just send the post and attached image. Do not preview thread, as this will lose the link to the image,

16.08.23 08:37
Tried to attach an image to a forum post. jpg, 32kB, 72dpi, no blanks, ... File name is correctly displayed, but when I click "Preview Thread" it just vanishes. Help!

23.02.23 21:29
Has anyone used the Leica DM500, any comments.

27.12.22 21:10
Thanks, Jan Willem! Much appreciated. Grin

19.12.22 11:33
Thanks Paul for your work on keeping this forum available! Just made a donation via PayPal.

09.10.22 17:07
Yes, dipterologists from far abroad, please buy your copy at veldshop. Stamps will be expensive, but he, the book is unreasonably cheap Smile

07.10.22 11:55
Can any1 help out with a pdf copy of 1941 Hammer. Vidensk. Meddel. Dansk Naturhist. Foren. 105; thank you

Render time: 2.17 seconds | 196,105,581 unique visits