Posted by Tony T on 02-08-2007 16:10
#1
31 July 2007, New Brunswick, Canada.
Tabanid season is winding down with just a few species active in August. One very abundant species in August is
Tabanus nigrovittatus, on salt marshes. This head shot shows characteristics that separate
Tabanus from
Hybomitra:
Tabanus: eyes bare (no hairs); eyes often without stripes or pattern;
absence of an ocellar tubercle at top of frons.
Posted by jorgemotalmeida on 02-08-2007 18:17
#2
Tabanus glaucopis has 3 stripes on the eyes. :) Is there any exception for hairy eyes in Tabanus?
Posted by Zeegers on 02-08-2007 18:48
#3
Yes, there is. T. quatuornotatus has 3 bands and hairy eyes, still is a Tabanus.
So, eyes bare and/or other number than 3 bands implies Tabanus,
but the opposite is not true.
On the other hand, nearly each larger horsefly with 2 large orange sidemarkings is bound to be Hybomitra, with T. tergestinus as notorious exception.
In all cases, the tubercle feature as mentioned by Tony is decisive...
(and even then, in H. peculiaris group it is reduced....)
This is all Old World truth
Theo