Diptera.info :: Miscellaneous :: General queries
 On the pair Gonia divisa/foersteri
|
|
| KWQ |
Posted on 18-02-2010 14:38
|
|
Member Location: Turku, Finland Posts: 208 Joined: 10.12.04 |
I was just comparing two Gonias collected least spring in the south-western archipelago of Finland using the T & H key. And I was surprised, the other of my yellow-headed (not whitish nor yellowish pollinose) specimens keyed out right in G. foersteri , which would be a Central European rarity! Far out... I had 2 divisa specimens at hand and the differences were as follows: Divisa: Abdomen largely red at sides. Width of parafacialia slightly narrower than width of eye "Foersteri-candidate": Abdomen practically black with only a slight trace of red coloration at sides. Width of parafacialia the same or slightly more than width of eye. At this guess I would simply presume this lies within the variation of divisa, but could anyone confirm this or somehow comment this case/these species? |
|
|
|
| Zeegers |
Posted on 18-02-2010 17:49
|
|
Member Location: Soest, NL Posts: 19104 Joined: 21.07.04 |
Dear KWQ Your point is well known. Some material from Finland is rather foersteri-like, but might be melanistic divisa. I did send some material to Ziegler in Berlin and quite coincidentally, I will visit Ziegler next week. So I will ask for his opinion. Theo |
|
|
|
| KWQ |
Posted on 19-02-2010 20:08
|
|
Member Location: Turku, Finland Posts: 208 Joined: 10.12.04 |
Thanks for your reply! It's always consoling to notice at least that your wildest fantasies can be shared by somebody else... I met JariF today and he told that he had encountered a similar case here in Finland. |
|
|
|
| Zeegers |
Posted on 06-03-2010 10:00
|
|
Member Location: Soest, NL Posts: 19104 Joined: 21.07.04 |
so, i have seen foersteri last week in coll. Ziegler. It is very very different, very large and very elongated. The specimens here are clearly melanistic divisa, as also does occur in ornata. It seems these dark divisa occur in colder habitats, like marshes Theo |
|
|
|
| KWQ |
Posted on 07-03-2010 10:26
|
|
Member Location: Turku, Finland Posts: 208 Joined: 10.12.04 |
Thanks a lot Theo! I already showed this specimen to Mr. Haarto, and he agreed with this melanism theory. Case closed. |
|
|
|
| KWQ |
Posted on 07-03-2010 10:27
|
|
Member Location: Turku, Finland Posts: 208 Joined: 10.12.04 |
I just add that the habitat was just a usual roadside/wasteland this time. |
|
|
|
| Jump to Forum: |