The First Data on Brain Parasites of the Genus Frenkelia (Protista: Coccidia) in some Small Rodent Species in Lithuania

All 560 individuals of small rodents belonging to six species of the families Cricetidae and Muridae were trapped in different habitats of various districts in Lithuania in 1995–2001. To determine Frenkelia infection, brain samples were examined. Cysts of Frenkelia were detected in the brain of three vole species only. The average rate of infection in bank voles (Clethrionomys glareolus) was 21.1%. With different localities the prevalence of Frenkelia infection varied significantly (from 0.0% to 60.6%). Only one out of 35 root vole (Microtus oeconomus) and one out of 24 short-tailed vole (M. agrestis) individuals contained cysts. There were two Frenkelia species established in voles: F. glareoli in C. glareolus and F. microti in M. oeconomus and M. agrestis. All the 23 examined common vole (M. arvalis), 31 striped field mouse (Apodemus agrarius) and 106 yellow-necked mouse (A. flavicollis) individuals were uninfected. These results turn to be the first contribution to the investigation of the Frenkelia fauna, its prevalence and distribution among certain mouselike rodent species in the Baltic States.