In this study, a new genus and species of neogregarine which is a pathogen of Anisoplia segetum Herbst (Coleoptera: Scarabaeidae), is described. The adult beetles of A. segetum were collected from Nevsehir, Turkey and neogregarine infection rates were determined as 18.52%. The Giemsa-stained mature oocysts are lemon-shaped and measured 9.34 +/- 0.82 mu m in length and 5.77 +/- 0.77 mu m in width. The oocyst wall surface of the mature oocysts is similar to an osage orange (tuberculate). Morphological, ultrastructural and molecular features indicate that the previously undescribed neogregarine is dissimilar to all known neogregarine taxa and represents the first record from Anisoplia segetum and is named here as Aranciocystis muskarensis n. gen., n. sp. (C) 2017 Elsevier Inc. All rights reserved.