In the past decade, several species of platygastroid wasps were found to be adventive in North America and Europe while under evaluation in quarantine as biological control agents of invasive pests. The scope and relative risk of this phenomenon is not fully known, but it is clearly a trend with implications for classical biological control. As a means of assessing the issue and to provide a global baseline, we implemented a data-mining approach with DNA sequences in the Barcode of Life Database, yielding 201 platygastroid BINs with intercontinental and island distributions. At least fifty-five BINs displayed exact COI barcode matches across continents, with many more BINs scored as inconclusive due to sequence length variation. These intercontinental and island BINs include biocontrol agents known to be adventive, as well as many species identified only to genus with uncertain geographic origins. We provide 2,500 identifications for platygastroid BOLD BINs, 88% to genus, to encourage additional research on this distributional phenomenon. The intercontinental BOLD BINs were compared to literature records and GBIF occurrences of cosmopolitan species to identify gaps and discordance across data sources. Smaller COI barcode datasets from localities in Florida and Germany, including topotypical specimens, revealed more intercontinental matches. We analyzed COI sequences in BOLD for the entirety of Insecta and Araneae to assess this phenomenon more broadly and because these taxa contain many hosts for platygastroid wasps. This method revealed that the intercontinental distribution phenomenon is widespread with implications for assessing biological diversity, taxonomic methodology and regulatory frameworks.

A morphological and molecular analysis of Gryon Haliday (Platygastroidea, Scelionidae) was conducted to provide a taxonomic and phylogenetic context for a species under evaluation as a biological control agent of Bagrada hilaris (Burmeister) (Hemiptera, Pentatomidae). Our analysis revealed that Gryon is polyphyletic and that the biological control agent is not G. gonikopalense , a name that was tentatively applied to this species in 2019. We here describe this species as new, Gryon aetherium Talamas sp. nov. , and resurrect the generic name Hadronotus Förster. Morphological characters that delimit our concepts of Gryon and Hadronotus are presented. Based on morphological characters and multilocus phylogenies, we determined that five presently valid scelionid genera belong within Gryon . In total, 15 species are transferred into Gryon from these genera, 215 species are transferred from Gryon to Hadronotus , and 6 species are transferred from Gryon to Dyscritobaeus Perkins. Specimens collected during field studies in California and reevaluation of specimens determined as G. myrmecophilum in Mexico reveal that G. aetherium is adventive in North America.