Thread subject: Diptera.info :: Hydrophorus oceanus (was: Orthoceratium?)

Posted by Klaas on 03-12-2008 19:42
#1

Netherlands, Waddenzee, near Moddergat, 24-7-2008.
On clay in salt water area.

Species is ca 6,5 mm.

Thank you in advance,

Klaas


dorsal view

Edited by Klaas on 04-12-2008 22:05

Posted by Klaas on 03-12-2008 19:43
#2

also dorsal, more magnified

Posted by Igor Grichanov on 04-12-2008 08:31
#3

No, it is Hydrophorus.
Compare with wing of Orthoceratium lacustre

Edited by Igor Grichanov on 04-12-2008 08:33

Posted by Klaas on 04-12-2008 10:20
#4

After i focused on hydrophorus just on general appearance, i neglected it because of the size of the fly (6,5 mm).
Now i start to believe i must be mistaken in that meassurement.

It has only two spines at scuttelum, so it should be Hydrophorus oceanus? Do you agree in this ?

Thank you Igor.

Klaas

Posted by Igor Grichanov on 04-12-2008 16:27
#5

Hydrophorus oceanus. Why not? If you are sure that the lateral setae on scutellum are not broken or covered with wing base. Body size of oceanus is 2.1-3.8 mm. Body size together with wing (as well as leg span) on your doli photo can reach 5-6 mm.

Edited by Igor Grichanov on 05-12-2008 09:29

Posted by Klaas on 04-12-2008 19:17
#6

I allways write down the bodylength, without the wings.
I believe you are right about the species, but a mismeasurement of 200 % in size makes it a bit uncomfortable for me.

I am pretty sure about the two bristles on scuttelum, so i think that i must keep this one for Hydrophorus oceanus.
I have no idea wether that species is rare or commen at the Dutch coast.

Klaas