A close examination of the collar would be required to confirm this, but it appears to be worked in a type of brick stitch, not netting [see the horizontal beads at the intersections of the weave?]. If so, if might be an Ecuadorian Saraguro collar.
http://www.saraguro.org/beadwork2.htm
The way the beadwork is suspended from the initial string of beads also looks very Sararuro to me, although the color combination doesn't seem to be - that looks more Zulu! But I don't know whether the Panamanian collars are also worked in the same manner as the Saraguro "Llano" collars.
Again, the weave would have to be examined closely to determine the actual technique used. If it is in fact not netting, that would eliminate African or Russian beadwork.