Nota bene: The taxonomy of the genus Ophrys is somehwat of a contentious topic. Many taxa have been described as species, but there is ongoing discussion whether these taxa should indeed be recognized at the species level. As a result, the number of recognized species varies tremendously from author to author; Véla et al. (2008) report that this number ranges from 10 to 250!
In the field, one immediately notices the rich variability of many taxa. If one adheres to narrowly defined taxa, it is not exceptional to find specimens that cannot with certainty be identified; quite often the narrowly defined taxa seem to blend into one another without crystal clear boundaries. This rather unsatisfactory situation would still be acceptable if it were supported by independent evidence, for instance from genetic studies. However, the genetic evidence points in the direction of fewer rather than more species (Devey et al. 2008). As long as the debate has not been settled, I choose to follow The Pant List, which tends to be rather conservative in accepting various taxa.