Hi Paride,
As I try to use this forum to learn things (as well as getting determinations from experts) and the experts seem to disagree in this case (to some extend) I tried to look at the animals at hand a little more closely to see if I might understand what's going on ...
Original von Paris The head is longer than the distance between eyes.
- How secure/pertinent is that character?
- How should one measure it in the first place?
- What is the relative size indicated for A. roeselii??
I did a little bit of tinkering with the different images that the Forum provides and an additional one from Wikimedia Commons - most of which were determined as A. roeselii, but almost all seem to have a head longer than the distance between the eyes except for the one previously determined as longiceps - that is, if I "measure" the character correctly??? Of course my measurements in the images are not very precise, so that may account for some variation too, but it does make me wonder how I should interpret the "determination rule" you presented above ??
The images are these:
© Axel Steiner → Thema
Org.det.:A. roeselii |
(headsize) | Length of head about same as distance between center lines of eyes. |
© Svenja Christian → Thema
Org.det.:A. longiceps/roeselii |
(headsize) | Length of head about the same as distance between outer sides of eyes. |
© Markus Schwibinger → Thema
Org.det.:A. longiceps |
(headsize) | Length of head about the same as distance between inner sides of eyes. |
© Rainer Altenkamp Wikimedia Commons
Org.det.:A. roeselii |
(headsize) | Length of head about the same as distance between center lines of eyes. |
Am I looking at the wrong sizes/measurements?
An additional question would concern the listed host plants for A. longiceps, as the animal that Axel Steiner presented here was found on Alder (Alnus), with no Platanus in the vicinity. Is Alder also a known host for A. longiceps?
Thanks in advance for any additional infos/thoughts!
Cheers, Arp
P.S. @Ringo: Wenn Du Deine Gedanken zu den Kopfabmessungen oder sonnstwas mit uns teilen möchtest dann wäre das natürlich auch sehr wilkommen.
Please ignore the attachment - it is only needed to provide the adapted version of Axels image above.