Thread subject: Diptera.info :: Good ol' Pollenia (14.12.08) --> P. cf. rudis

Posted by Juergen Peters on 14-12-2008 21:02
#1

Hello!

This male sunbathing at the forest this afternoon (northwest Germany) was rather large (10 mm+). Any characters that could delimit possible species?


1100x1100 pic (150 KB):
http://www.foto-u...0mm_M2.jpg

Edited by Juergen Peters on 28-11-2017 21:54

Posted by Juergen Peters on 14-12-2008 22:16
#2

Another big, dark one from today from a stake on a meadow with apple trees.

Posted by Juergen Peters on 14-12-2008 22:17
#3

Same individual as No. 2.

Posted by Susan R Walter on 14-12-2008 23:24
#4

Male Pollenia are the most frustrating creatures. You can have whizzed half a dozen neatly through the key and be starting to get smug, thinking 'aha, I am getting the hang of these' then you will get two in a row that just will not come out the other end of the key with a name :@

I currently hate Pollenia, but just for you, Juergen, I will say this:

Not amentaria – dusting on abdomen clearly tessellated and shifting, not weak with lots of shining black.

Not vagabunda – no dark median vitta between pre acr.

Pediculata
? hmm...basicosta appears black, which would eliminate. Can't see key character which is bunch of pale curly hairs on node of humeral x-vein and Sc. This feature is on the underside, so never going to be visible in photos.

Not griseotomentosa - large size of the above specimens eliminates this rather small species, as well as lack of dark median line and posterior margins of tergites.

Dark basicosta probably eliminates rudis, angustigena and pallida.

Could be labialis.

But it's a bit 'could' and I wouldn't like to swear to it.

Posted by Juergen Peters on 14-12-2008 23:47
#5

Hello, Susan!

Many thanks for explaining this! I previously thought, the females of Pollenia were so difficult (males, too, but not as impossible as the females). Must have confused that...

Edited by Juergen Peters on 14-12-2008 23:48

Posted by Susan R Walter on 15-12-2008 14:53
#6

No, you didn't confuse it. Females are impossible, not just difficult. :(

Posted by johnes81 on 28-11-2017 14:37
#7

The color of the basicosta is helpful with Lucilia but not Pollenia. The basicosta of the rudis group can be yellow, brown or dark brown/black. I have yellow and black from two different rudis specimens. According to Dr. Rognes, the features mentioned in his publications have "no taxonomical value." In other words, the features are unreliable.

The photos here depict a species of the rudis group in my opinion. I cannot see golden vestiture which can rule out angustigena. Notice that t2 has 2 ad setae.

I'm very comfortable suggesting a male Pollenia rudis.

Posted by Juergen Peters on 28-11-2017 21:54
#8

Hello,

johnes81 wrote:
The photos here depict a species of the rudis group in my opinion. I cannot see golden vestiture which can rule out angustigena. Notice that t2 has 2 ad setae.
I'm very comfortable suggesting a male Pollenia rudis.


many thanks!