The use of a serological technique to examine host selection in a natural population of the medicinal leech, Hirudo medicinalis

SUMMARY. 1. Serological examinations were made of the bloodmeals of medicinal leeches, Hirudo medicinalis L., collected from two sites at Dungeness, Kent, in order to determine their host range.
2. A modified miniature Ouchterlony agar diffusion method was used with antisera raised in rabbits against fish, bird, frog and mammal blood sera.
3. The results suggest that the marsh frog. Rana ridibunda Pall., was the most important host with smaller contributions from birds and fishes. Mammals appeared to be very rare hosts. These results reflect the availability of hosts as determined by field studies. Many leeches showed evidence of blood meals from more than one host.
4. Field observations indicated the importance of the smooth newt, Triturus vulgaris L., as a host for the leech, particularly early in the season. Predation on the newt appeared invariably to be fatal.