Efficacy of the nematophagous fungus Duddingtonia flagrans in reducing equine cyathostome larvae on pasture in south Louisiana.

The research article experiments on the effectiveness of the fungus, Duddingtonia flagrans, in reducing the prevalence of equine cyathostome larvae on pasture grounds in the temperate climate of South Louisiana.

Study Objective and Experiment Methodology

• The main focus of this study was to evaluate the efficiency of the fungus Duddingtonia flagrans in combating equine cyathostome larvae in the subtropical environment of southern Louisiana. Previously, the fungus’s effectiveness was shown in colder, temperate climates.
• To this end, fecal pats were prepared by combining feces from a parasite-free horse (that had been fed D. flagrans) with feces from a parasitized horse containing cyathostome eggs. For control purposes, fecal pats were prepared using feces from a parasite-free horse and feces from a parasitized horse without the fungus feeding.
• The prepared fecal pats were then placed on pasture grounds in six replicates, periodically, over intervals of 4 weeks from March 1997 until January 1998. The effect of the fungus on the larvae was measured by recovering L3 (third stage larvae) from the grass around the fecal pats of the treated and control groups.

Observations and Findings

• The study showed a notable reduction of L3 survival in the field during the significantly warm months of May, June, July, August and September, as compared to L3 cultured in a lab environment.
• Most importantly, D. flagrans was observed to have a significant impact on reducing L3 survival during the months of April, May, and from October 1997 to January 1998, with reported reductions ranging from 66% to 99%.
• Moreover, the study showed the overall effectiveness of D. flagrans in managing cyathostome larvae for the entirety of the year, illustrating that this fungus could be a valuable tool in managing these parasites in subtropical climates like Louisiana.