Thread subject: :: flies on oak tree sap

Posted by elck on 30-07-2005 20:55

On an oak tree I saw a lot of wasps in a frenzy over the trees' sap.
On closer observation I also saw these flies.
In extreem dark circumstances so I had to spike the pictures considerably.
Any ideas?

Edited by elck on 30-07-2005 23:39

Posted by Paul Beuk on 30-07-2005 23:14

They are Drosophilidae, belonging to the Drosophila genera complex. I will try to find out which one it is.

Posted by elck on 30-07-2005 23:40

thanks, is it known behaviour?

Posted by Paul Beuk on 31-07-2005 09:32

Numerous species may come to fermenting substances of any kind. Several seem to prefer fermenting tree sap, among others the species of the (former sub-)genus Scaptodrosophila, including the species S. deflexa and S. rufifrons. Moreover, some other (morphologically different) genera can be found near sapruns as well, for example Amiota, Leucophenga and Stegana.

Posted by elck on 31-07-2005 11:28

Apart from the wasps vespula vulgaris I also observed Atalanta butterflies vanessa atalanta .
It's always a good place to see insects from near by.
Thanks for the reply.

Edited by elck on 31-07-2005 11:29