DISTRIBUTION OF POTENTIAL INTERMEDIATE HOSTS FOR FASCIOLA-HEPATICA AND FASCIOLOIDES MAGNA IN MONTANA, USA

A collection of lymnaeid snails in Montana was made over a 3 year peri od, in conjunction with a state-wide survey of the distribution of liv er flukes in Montana. Collection areas were selected based on reports of infected cattle, sheep or wildlife, and with the intent of covering all geographic regions of the state. Snails were found at all 97 of t he locations chosen for collections, with lymnaeids collected at 71 of the locations. The 97 sites were located in 28 of Montana's 56 counti es. Nine lymnaeid species were collected, five of which have been repo rted either as natural or experimental intermediate hosts for Fasciola hepatica or Fascioloides magna. The two snail species most widely dis tributed over the areas enzootic for the flukes were Lymnaea modicella and Lymnaea caperata.