STUDIES ON THE HOST SPECIFICITY OF THE MEDICINAL BLOOD LEECH HIRUDO-MEDICINALIS L

For the identification of host species of blood-sucking parasites, the suitability of disc-electrophoresis of the stomach contents was teste d. Mammalian blood in the stomach of the medicinal blood leech Hirudo medicinalis gave satisfactory results. In the case of mixed blood samp les from H. medicinalis, the identification of the host according to t he electrophoretic patterns of the stomach contents failed as compared with an immunological method such as the Ouchterlony test. Medicinal blood leeches (H. medicinalis) collected in Istria Croatia, or bought in a pharmacy contained blood from cattle, horses, or frogs in their s tomachs. Specimens of H. medicinalis from Lake Neusiedl or from the Se ewinkel Austria, had sucked blood from mallards or frogs. Blood of cat tle. mallards, and frogs was found in the stomachs of H. medicinalis c oming from the National Park Kiskunsag Hungary. For the first time, ho rses were established as hosts for free-living specimens of H. medicin alis. A comparison of the weights of H. medicinalis bought in a pharma cy revealed that specimens containing frog blood in their stomachs wei ghed significantly less than those containing horse blood. These resul ts confirmed the reports from Ssynewa (1944) concerning the breeding e xperiments. Probably, there is a change in hosts from the frog to warm -blooded animals during the life cycle of H. medicinalis. There were a lso significant differences in the weights of leeches as revealed by a comparison of the population from the Neusiedlersee with the leeches bought in the pharmacy.