The present study describes the first isolation and characterization of Vairimorpha plodiae, a microsporidian pathogen of Plodia interpunctella (Lepidoptera: Pyralidae), from Turkey. We present characteristic light and electron microscopical features of the spores. Fresh binucleate spores are oval and measure 4.48 +/- 0.23 (4.01-4.84) mu m in length and 2.21 +/- 0.15 (1.91-2.48) mu m in width. Ultrastructural studies showed that the spore wall measures 150 to 200 nm and consists of a clear endospore (125-150 nm) and an electron-dense, uniform, thin exospore (30-50 nm). The polar filament is isofilar and with 10-12 coils. The well-developed polaroplast consists of two parts with thin lamellae anteriorly and thick, irregularly arranged lamellae posteriorly. The identity of our isolate is discussed.