SPATIAL AND TEMPORAL ABUNDANCE OF GASTROPOD INTERMEDIATE HOSTS IN NORTHEASTERN MINNESOTA WITH IMPLICATIONS FOR PARELAPHOSTRONGYLUS TENUIS RISK IN MOOSE

Abstract

Parelaphostrongylus tenuis is a nematode meningeal parasite that requires white-tailed deer primary hosts and terrestrial gastropod intermediate hosts to complete its life cycle. While white-tailed deer are the only host in which P. tenuis can complete its life cycle, P. tenuis can be lethal to moose and other cervids that accidentally ingest infected gastropods while browsing. Describing the spatial and temporal changes in gastropod abundance will increase understanding about the risk of P. tenuis infection by moose at the individual and population levels. We used cardboard traps and hand searches to estimate terrestrial gastropod species composition and abundance in representative vegetation communities in Northeastern Minnesota. We also tested the gastropods for P. tenuis infection. We also measured various environmental factors that may explain terrestrial gastropod distribution. Gastropods were most abundant in conifer and regenerating forests (11.2/m2) while mixed forests had the lowest gastropod abundance (7.0/m2). Gastropods were more abundant in September than June and July and none were collected in November. Seventy four gastropods were found climbing on vegetation up to three meters off the ground. 0.1% of the identified gastropods were infected with P. tenuis. Spatial and temporal changes in gastropod abundance could provide different risk levels of P. tenuis infection for moose. Our research will help to evaluate infection risk in the most common moose habitats in Northeastern Minnesota.