Chelostoma nasutum

Müller, Andreas, 2015, Palaearctic Chelostoma bees of the subgenus Gyrodromella (Megachilidae, Osmiini): biology, taxonomy and key to species, Zootaxa 3936 (3), pp. 408-420 : 416

nasutum species group

Preoccipital ridge sharp but not raised to a carina. Basal zone of propodeum weakly sloping to nearly horizontal and usually about as long as metanotum. Anterior surface of tergum 1 all in one plane except for longitudinal groove. Females: Clypeus strongly protruding and nose-like ( Fig. 17 ) except for C. handlirschi , whose clypeus is of similar shape than that of C. rapunculi ( Fig. 14 ). Males: Median elevation on sternum 2 of different shape among species ( Fig. 15, 16, 18, 19 ), but not triangular in lateral view, its posterior surface neither evenly sloping nor of half-elliptical shape but slightly to distinctly concave. Apical zone of sternum 4 densely covered with short and apically bent yellowish bristles. Tergum 7 bipartite.

Figures

FIGURE 11 – 19. 11: Chelostoma orientale, head of female. 12: Chelostoma orientale, sternum 2 of male. 13: Chelostoma orientale, sterna 3 – 6 of male. 14: Chelostoma handlirschi, head of female. 15: Chelostoma handlirschi, sternum 2 of male. 16: Chelostoma aegaeicum, sternum 2 of male. 17: Chelostoma nasutum, head of female. 18: Chelostoma nasutum, sternum 2 of male. 19: Chelostoma hebraeum, sternum 2 of male.