Microsporidia in the springtailIsotomurus fucicolus(Collembola, Isotomidae) and possible pathways of parasite transmission

Detection of a microsporidium infecting male gonads of Isotomurus fucicolus is reported. An ultrastructural study of the developmental stages of the parasite revealed that it was diplokaryotic during all stages of life and apansporoblastic. Mature spores were broadly oval, with a thick wall, and contained a lamellar polaroplast and an isofilar polar filament with a maximum of 13 turns coiled in a single layer. These findings suggest that the organism belongs to the large heterogeneous genus Nosema. Possible pathways of transmission of the parasite are discussed.