On the classification of sphecodine bees (Hymenoptera: Halictidae)
Authors: Engel Michael S. 
Published: January 2024

Taxonomic notes are presented for the exclusively cleptoparasitic halictine bee subtribe Sphecodina (Halictinae: Halictini). Keys are presented to the Western and Eastern Hemisphere genera of Sphecondina. In the New World fauna, the genusMelissocleptisGonçalves is considered a subgenus ofAustrosphecodesMicheners. l., and the following species transferred:Austrosphecodes(Melissocleptis)albifacies(Gibbs),A. (M.)capriciosus(Schrottky),A. (M.)coriae(Moure & Hurd),A. (M.)diablotinus(Gibbs),A. (M.)genaroi(Engel),A. (M.)nigritus(Ashmead),A. (M.)tainoi(Engel),A. (M.)variabilis(Schrottky) comb. n. A key is provided to the subgenera ofMicrosphecodesEickwort & Stages. l., withTrichosphecodessubgen. n., established for those species with elongate ocular setae. Keys are also presented for the species ofMicrosphecodes s. str. andTrichosphecodes, along with the descriptions of the speciesMicrosphecodes(Microsphecodes)eickwortisp. n.,M. (M.)multirugosussp. n.,M. (M.)quechuasp. n., andM. (Trichosphecodes)trichophthalmussp. n. The Brazilian speciesNesosphecodes depressusGonçalves is transferred toNotoclopsgen. n., resulting in the new combinationNotoclops depressus(Gonçalves) comb. n. A key is presented to New World subgenera ofSphecodesLatreille, with the following new or resurrected groups:ProteranerRobertson,DrepaniumRobertson,SphecodiumRobertson,Asphecodiumsubgen. n., andBoreosphecodessubgen. n. The following new species are described among New WorldSphecodes:Sphecodes(Asphecodium)brevisulcatussp. n.,S. (Sphecodium)eustaurossp. n.,S. (S.)electrumsp. n.,S. (Sphecodes)zacatuchesp. n. The genusCaenosphecodesgen. n. is proposed forSphecodes pseudoredivivusAstafurova & Proshchalykin andS. redivivusBlüthgen, differing fromSphecodesby the elongate free part of the marginal cell, in this respect resembling New WorldMicrosphecodes. This results in the combinationsCaenosphecodes pseudoredivivus(Astafurova & Proshchalykin),C.sauteri(Meyer),C. simlaensis(Blüthgen), andC. redivivus(Blüthgen) comb. n. The currently employed characters for subgenera ofEupetersiaBlüthgens. l. fail to distinguish the groups. Accordingly, the key to subgenera is revised and the species newly organized as to subgenera.Cephalosphecodessubgen. n. is established forEupetersia macrocephalaPauly andE.mandibulataBlüthgen,Xanthocleptissubgen. n. is proposed forE.reticulata(Benoist), andPollinicleptissubgen. n. is erected forE.nathaniBaker,E.malayensis(Blüthgen),E.sabahensisPauly, andE.singaporensisPauly. A new species ofNesoeupetersia,E. dnopherasp. n., is described from Sabah, Malaysia and a tentative key provided to species of the subgenus.ThrausmusBuysson andCallosphecodesFriese are treated as independent genera, and the latter considered close toMelittocleptesgen. n., withMelittocleptes insularis(Smith) comb. n. as type species. A key is presented to Old World subgenera ofSphecodes, with the following new or resurrected groups:Proteraneropsissubgen. n.,Paradrepaniumsubgen. n.,Eusphecodessubgen. n.,SabulicolaVerhoeff,Caenocleptessubgen. n.,Xystoclopssubgen. n.,Callocleptessubgen. n., andNomiocleptessubgen. n.