The flower fly genus Eosalpingogaster Hull, predator of the carminic acid producer cochineal (Dactylopiidae), is revised. Two new species are described (knutsoni sp.n. and umbra sp.n.) and an identification key is provided for all known species. Diagnoses, illustrations, synonymies and distributional and biological data are given. Three new synonyms are proposed [texana Curran as jun.syn. of cochenillivora (Guerin-Meneville); liposeta Fluke and dactylopianus Blanchard as jun.syn. of nigriventris (Bigot)] and two lectotypes are designated for cochenillivora (Guerin-Meneville) and nigriventris (Bigot). Eosalpingogaster is elevated to full generic status based on adult morphological characters, biological data and a new phylogenetic analysis of molecular characters with genes 28S, 18S and cytochrome c oxidase subunit I. All data, images and drawings are available online as an example of the utility of international standards for biodiversity informatics.
