Abstract
Trematodes of the genus Dicrocoelium are one of the most common parasites in ruminant animals; however, their life cycles in Japan are unclear. To find the sporocysts of D. chinensis in the natural field, we sampled 269 land snails (14 species) at a location with high level infection of sika deer in Gifu Prefecture, Honshu Island, Japan in autumn between 2017 and 2019. During the sampling period, we found mother sporocysts in the hepatopancreas of Aegista vulgivaga and Cyclophorus herklotsi. DNA barcoding based on the sequences of cytochrome c oxidase subunit 1 showed that the sporocysts from A. vulgivaga belonged to D. chinensis, indicating that this snail has potential as the first intermediate host of D. chinensis at this location.