Jizz is the 'je ne sais quoi' of a fly's being, the not easily defined mix of characters which identify a taxon.
This is the concept of gestalt and the family species is a gestalt entity. A gestalt entity is a physical, biological, psychological, or symbolic configuration or pattern of elements, so unified as a whole that its properties cannot be derived from a simple summation of its parts.
Hi. Please delete all photos of E. carrapateira I've uploaded. I did not remember that I already had uploaded that species in particular. Except the pallidifacies (this was not present yet). Thank