Sceliphron caementarium (Drury, 1770) (Fig. 1).

Material examined: Bulgaria, Sofia, Druzhba II sub., 30.IV.2012, 1 ♀, T. Ljubomirov leg. & det. (IBER); Bulgaria, Black Sea Coast, Varna, University Botanic garden, 43°14'06.6''N, 28°00'05.94''E, 55 m a. s. l., 11.VI.2012, 1 ♀, A. Gerasimov leg., D. Gradinarov det. (BFUS); the same locality, but 24-28.VII.2013, 1 ♀, D. Dimitrova leg., D. Gradinarov det. (BFUS) .

Natural distribution of the species from genus Sceliphron Klug, 1801 includes temperate and tropical areas, as the most of the species are found in the Old World (Bohart & Menke 1976). In Bulgaria, three native species of the genus are presented - S. destillatorium (Illiger, 1807), S. spirifex (Linnaeus, 1758) and S. madraspatanum tubifex (Latreille, 1809) (Pulawski 2017) . Along them, alien Asian species S. curvatum (F. Smith, 1870) have been reported for Bulgaria (Jacobs, 2005) and recently it is widely distributed in the country (Guéorguiev & Ljubomirov, 2009). S. caementarium, native for North and Central America (Bohart & Menke 1976), is now presented in many region of the World (Pulawski 2017). The species has been accidentally introduced to Europe, probably several times (Bogusch & Macek 2005). To date, in Europe, S. caementarium is established for Belgium, Luxembourg, France, Germany, Austria, Switzerland, Czech Republic, Slovakia, Croatia, Italy, Spain, Portugal and Ukraine (Turrisi & Altadonna 2017).