The rarely recorded Polysphincta longa is probably widely overlooked in Europe as a result of confusion with the morphologically similar] P. boops. Characters for the separation of these species are given, and host and distribution records, largely based on recent fieldwork, are presented. Araneus angulatus is shown to be the hitherto unknown host of] P. longa, while all rearing records for] P. boops are from Araniella species. I P. longa is reported as new to the fauna of the United Kingdom and] P. boops as new to Estonia.