Chelostoma grande (Nylander, 1852)

Müller, Andreas, Pisanty, Gideon & Dorchin, Achik, 2025, Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species, Zootaxa 5717 (3), pp. 329-369 : 341

Chelostoma grande species group

The four representatives of the Chelostoma grande species group are characterised in both sexes by a very long proboscis ( Fig. 10, 11 ). Additional characters of the females are the large body length, which is at least 8 mm but mostly longer, the basally distinctly constricted terga 2-3 ( Fig. 10 ), and the long labrum, which is at least 2.5× as long as apically wide ( Fig. 13 ). An additional character of the males is the presence of two sharp and tooth-like projections on the hypostomal area formed by the hypostomal carinae in the basal half ( Fig. 16 ). The species are oligolectic on Dipsacoideae ( Caprifoliaceae ), most likely including C. scabiosae , for which only one pollen load was available for study.

Figures

FIGURES 10–18. Chelostoma scabiosae: 10: Female, 11: Male, 12: Clypeus and labrum of female in lateral view, 13: Labrum of female, 14: Basal area of propodeum of female, 15: Terga 5–7 of male, 16: Hypostomal carina of male, 17: Sterna 2–4 of male, 18: Genitalia of male.