| system | Vitae - living organisms |
| domain | Eukaryota Whittaker & Margulis, 1978 - lifeforms with nucletic cells |
| superregnum | Unikonta |
| system | Opisthokonta Cavalier-Smith, 1987 |
| kingdom | Animalia Linnaeus, 1758 - animals |
| subregnum | Eumetazoa Butschli, 1910 |
| divisio | Bilateria Hatschek, 1888 - bilaterians |
| subdivisio | Protostomia Grobben, 1908 - protostomes |
| phylum | Arthropoda Gravenhorst, 1843 - arthropods |
| subphylum | Hexapoda Blainville, 1816 - hexapods |
| class | Insecta Linnaeus, 1758 - insects |
| subclass | Pterygota Lang, 1888 |
| infraclass | Neoptera Martynov, 1923 |
| cohors | Endopterygota Sharp, 1898 |
| order | Hymenoptera Linnaeus, 1758 - bees, ants and wasps |
| suborder | Apocrita Gerstäcker, 1867 |
| superfamily | Apoidea Latreille, 1802 |
| family | Crabronidae Latreille, 1802 |
| subfamily | Crabroninae Latreille, 1802 |
| tribus | Crabronini Latreille, 1802 |
| subtribus | Crabronina Latreille, 1802 |
| genus | Crossocerus Lepeletier & Brullé, 1834 |
| species | Crossocerus walkeri (Shuckard, 1837) |