Holcostethus strictus and H. vernalis have been considered to be two separate species until recently. Josifov (1986a) treated them as subspecies; he has been followed in doing so by Lis (1990c). Many other recent workers have continued to recognize H. vernalis as a separate species, but all of these have been in lists or simple records of distribution; no one has as of yet refuted Josifov’s treatment.
The record from the Canary Islands needs to be confirmed (see Heiss & Ribes, 1992: 93).