Ancistrocerus from Sweden

[Alex]

I'm wondering what is considered to be "strongly shining and completely smooth" when talking about the propodeum in Ancistrocerus [as described in the "National Key" book, Douwes et al 2012]. Are these two shiny enought to be A. antilope, or is the propodeum truly shining in that species, ie without the heavy microsculpture seen here?

Caught at the same locality the 10th of July 2016 in Värmland, Sweden.

[Discoelius]

Hello
It's the [i]sides[/i] of the propodeum that are distinctive in A. antilope, not the posterior surface...

Cheers,

Discoelius.

[Alex]

Thanks, so thats why I'm confused, it talks about "sides and posterior surface" with a picture of the posterior surface. So thats wrong then, thanks for explaining it!

[Christian]

I do not agree. Current keys recognize A. antilope by the shiny posterior side (back side) of propodeum. I add a pic from my collection (female).

[Discoelius]

Hello
I don't know what is meant by "current keys" in this context, but in any case the morphology of A. antilope has not changed, so I think "older" keys and "older" diagnostic characters continue to be valid and useful to separate the species.
Traditionally, keys have mentioned both the sides and the posterior part of the propodeal dorsum as diagnostic for this species. In my experience the propodeal sides of antilope females are (at least posteriorly) very clearly shiny, and the propodeal sides of antilope males are both wholly and impressively shiny, while the propodeal sides are clearly matt in the other European species of the genus: this is such an extremely effective diagnostic character that I think there's no point in looking at the posterior part of the propodeal dorsum (I also think that the difference in the surface of the posterior propodeal dorsum between antilope and the other species is often subtle and therefore a less practical character). Moreover, in dry specimens the sides of the propodeum are usually easy to inspect, while the posterior part of the propodeal dorsum is often hard to impossible to inspect without relaxing the specimen, because it tends to be hidden by the base of the metasoma.

Cheers,

Discoelius.

[Christian]

I use the posterior side of propodeum for more than 25 year now as recognition character for A. antilope without any problems. It is also the main character used in most keys for Central Europe (in German language), current or old. So there is no need to look for other characters. However, of course are also other characters to recognize this species, and each one is free to use whatever he wants. Apart from this is A. antilope one of the very easy recognizable species in the genus and I don't think that we will get any advantage if we now value these characters in good or not so good.

Best wishes, Christian