Taxonomy of Nephrotoma guestfalica (Westhoff, 1879) (Diptera, Tipulidae), with the description of a new subspecies from Morocco

Northwest African material previously ascribed to the subspecies Nephrotoma guestfalica surcoufi (Pierre, 1925) proved to belong to two distinct morphological forms, the true N. g. surcoufi from Algeria, and Tunisia, and the here newly introduced Nephrotoma guestfalica vaillanti n. subsp. from Morocco. With the distinction of the new form, four subspecies of Nephrotoma guestfalica (Westhoff, 1879) are now recognized, all occurring in the western Palaearctic. An identification key for the males of the four taxa of Nephrotoma guestfalica s.l. is provided. The male terminalia of the four taxa are illustrated. The distribution of the four subspecies is summarized, based on material examined and published data. A map showing the currently known distribution of N. guestfalica surcoufi and N. guestfalica vaillanti is presented. Nephrotoma guestfalica guestfalica is recorded here for the first time from Croatia.