Key to Palaearctic species of Myiocephalus Marshall

1 Basal half of first metasomal tergite with laterope visible in dorsal view (Figs 6, 43); hypopygium of ♀ largely sclerotized, keeled ventrally, subtruncate or rounded posteriorly and with long setae (Figs 8, 37); length of malar space of ♀ 1.2–1.4 × basal width of mandible (Figs 11, 48), of ♂ 1.3–1.5 ×; ovipositor (except basally) slender (Figs 2, 36, 38); propleuron, pronotum ventrally and mesopleuron ventrally, pale yellowish; tegulum pale yellowish, paler than brownish humeral plate; middle coxa pale yellow or ivory (Figs 1, 36); occipital carina reaching dorsally near upper level of eye and sinuate laterally (Figs 11, 48). ................................................................................................... 2

- Basal half of first metasomal tergite straight laterally and nearly parallel-sided in dorsal view, without laterope visible (Fig. 24); hypopygium of ♀ largely membranous ventrally, unsclerotized, protruding latero-posteriorly and comparatively short bristly setae (Fig. 25); length of malar space of ♀ about equal to basal width of mandible (Fig. 28; of ♂ approx. 1.2 ×); only apical third of exserted ovipositor slender in lateral view (Figs 17, 20); propleuron, pronotum ventrally and mesopleuron ventrally, tegulum (darker than humeral plate), and middle coxa dark brown (Figs 17, 31); occipital carina dorsally distinctly below upper level of eye and straight laterally (Fig. 28)....................................................... M. niger Fischer, 1957

2 Area near occipital carina and occiput dorsally pale yellow (Fig. 10); mesopleuron of ♀ antero-dorsally largely finely coria- ceous and without rugae medially (Fig. 4; of ♂ indistinctly coriaceous antero-dorsally and largely smooth medially); width of face of ♀ 0.9 × combined height of face and clypeus (Fig. 9; of ♂ approx. 1.1 ×; measured from ventral rim of antennal socket to ventral border of clypeus: Fig. 15); length of malar space of ♀ 1.2 × basal width of mandible (Fig. 11; of ♂ 1.4–1.5 ×); head of ♀ strongly transverse in dorsal view (Fig. 10); mesopleuron and inner side of hind trochantellus yellowish brown (Figs 4, 6); scapus of ♂ hardly compressed (Fig. 15); [malar space of ♀ in anterior view nearly straight (Fig. 9)]; (lowland)......................................................................................... M. boops (Wesmael, 1835)

- Area near occipital carina dark brown and occiput dorsally brown (Fig. 47); mesopleuron of ♀ antero-dorsally largely rugulose and with some rugae medially (Fig. 41; of ♂ distinctly coriaceous antero-dorsally and largely smooth medially); width of face of ♀ equal to combined height of face and clypeus (Fig. 46; of ♂ approx. 1.1 ×; measured from ventral rim of antennal socket to ventral border of clypeus); length of malar space of ♀ 1.3–1.4 × basal width of mandible (Fig. 48); of ♂ 1.4–1.5 ×); head of ♀ slightly less transverse in dorsal view (Fig. 47); mesopleuron and inner side of hind trochantellus (except apically) dark brown (Figs 41, 43); scapus of ♂ distinctly compressed (Figs 52, 54); (montane)............ M. zwakhalsi van Achterberg, sp. n.