Nesting biology of Trypoxylon petiolatum Smith, 1858 (Crabronidae), a cavity-nesting solitary wasp new to Europe

We report on the discovery of the spider-hunting wasp Trypoxylon petiolatum (Crabronidae) nesting in three localities in the Province of Girona (Catalonia, NE Spain) in 2019 and 2021. This species is native to eastern Asia and has not previously been reported from Europe. We provide a detailed description of the species, as well as information on its nest architecture, cocoon shape, the identity of the spiders captured to provision the nests, and mortality rates, including parasitism by a native cleptoparasitic fly (Amobia signata, Miltogramminae, Sarcophagidae) and a native parasitoid wasp (Melittobia acasta, Eulophidae).