The effect of the nematode-trapping fungus Duddingtonia flagrans on free-living stages of horse strongyles - An experimental pilot study

FERNÁNDEZ, ALICIA SILVINA; LARSEN, MICHAEL; NANSEN, PETER

Bornholm

Simposio; XVIII Symposium of the Scandinavian Society for Parasitology; 1997

Scandinavian Society for Parasitology

The aim of this study was to determine the ability of the nematode-trapping fungus Duddingtonia flagrans to reduce the transmission of infective larvae of horse strongyle from experimentally deposited dung onto surrounding herbage. At three different times (June, July, and August) during the grazing season 1995, three groups of horses naturally infected with strongyles were fed three different doses of D. flagrans spored, while a fourth group remained as non-fungal fed control. Faeces from all four groups were deposited as artificial dung pats on a parasite-free plot. During two months, every second week after deposition, grass from specified areas surrounding each dung pat was cut, and the number of infective larvae on the herbage was determined. Additionally, faecal cultures from all groups of horses were set up to evaluate in vitro the larval reduction capacity of the fungus. After a dry period that apparently diminished the larvae transmission, the number of infective larvae escaping from dung pats to herbage was significantly reduced from mid-August onwards. Faecal cultures showed that D. flagrans survived the passage through the animals and was able to reduce significantly the number of infective larvae in vitro. This work has demonstrated the ability of D. flagrans to act as biological control agent against nematodes, reinforcing the idea that the use of nematode-trapping fungi is an useful toll in an integrated strategy to control nematode parasites.