Characteristic features of Nosema phyllotretae infecting Phyllotreta atra collected in Gumushane, Turkey are given in this paper. Fixed and stained spores are oval, 4.08 +/- 0.56 (range, 2.90 similar to 5.20) mu m in length and 2.53 +/- 0.33 (range, 1.80 similar to 2.90) mu m in width (n = 50) with 14 coils of the polar filament. The spore wall is 110 to 175 nm thick and made up of a clear endospore (90 to 125 nm) and a uniform exospore (50 to 64 nm). The anterior region of the polaroplast is thinly lamellar. The ultrastructural features of Nosema phyllotretae differ from those of other chrysomelid parasitic microsporidia.