Abstract
The large carpenter bees (Xylocopinae, Xylocopa Latreille) occurring in central Saudi Arabia are reviewed. Two species are recognized in the fauna, Xylocopa (Koptortosoma) aestuans (Linnaeus) and X (Ctenoxylocopa) sulcatipes Maa. Diagnoses for and keys to the species of these prominent components of the central Saudi Arabian be:: fauna are provided to aid their identification by pollination researchers active in the region. Females and males of both species are figured and biological notes provided for X. sulcatipes. Notes on the nesting biology and ecology of X. sulcatipes are appended. As in studies for this species from elsewhere, nests were found in (Lied stems of Calotropis procera (Aiton) (Asclepiadaceae) and Phoenix dactylifera L. (Arecaceae).