A revision of the bee genus Ancyloscelis (Hymenoptera: Apidae) in Argentina Author Schaller, A. Author Roig-Alsina, A. text Zootaxa 2021 2021-06-02 4980 3 521 540 journal article 5944 10.11646/zootaxa.4980.3.4 c50f1eed-a142-4d1b-a54b-b92dbb30e458 1175-5326 4897130 F5B71805-4E78-4B69-9146-797676C1A513 ursinus species group This group is characterized by the presence of hooked hairs on the mouthparts of the females ( Figs. 9A–B ). Hooked hairs are present on the stipes, on the prementum and on the first two segments of the labial palpus, except in A. halictoides , which lacks such hairs on the second segment of the palpus. One species, A. bonariensis , also has modified hairs on the hypostomal area of the head, on the trochanters, and on the metasomal sterna ( Fig. 9C ). Species of the group are 6.2–11.0 mm long. Males have a ventral tubercle in front of the middle coxa, except A. bonariensis which lacks the tubercles. Yellowish hairs are usually present on the metasomal apical bands and/or on the tibial scopa of females ( Fig. 1 ), and males of some species are entirely covered by golden pile ( A. ursinus , A. mesopotamica , A. duckei , and A. holmbergi ), or nearly so ( A. bonariensis ) ( Fig. 2 ).