[New species of microsporidians (Microsporidia, Nosematidae) from horsefly larvae in the Ukraine].

A new species of microsporidians, Stempellia lairdi sp. n., was found in larvae of Tabanus autumnalis L. from Ukraine. It affects the muscular tissue and haemolymph of horse fly larvae. Spores of the species are oval, egg-shaped, 1.8--7.6 x 1.2--3.8 mu in size. The species is pathogenic and causes the mortality of infected larvae.