Important morphological characters for species differentiation of the Austrian species of the Colletes succinctus group: (A–C) Female C. succinctus: A. Fovea facialis; B. Terga 1 and 2; C. Proboscis; (D–F) Female: C. collaris: D. Fovea facialis; E. Terga 1 and 2; F. Cuticle of frons; (G–I) Female C. brevigena: G. Fovea facialis; H. Terga 1 and 2; I. Cuticle of mesopleura; (J–L) Female C. hederae: J. Fovea facialis; K. Terga 1 and 2; L. Proboscis; (M–O) Female C. pannonicus: M. Fovea facialis; N. Terga 1 and 2; O. Clypeus. ant – antenna, ce – complex eye, fov – fovea facialis, oc – lateral ocellus, mxp – maxillary palpus, T1 – tergum 1, T2 – tergum 2.