THE POTENTIAL OF NEMATOPHAGOUS FUNGI TO CONTROL THE FREE-LIVING STAGES OF NEMATODE PARASITES OF SHEEP : PASTURE PLOT STUDY WITH DUDDINGTONIA FLAGRANS

Abstract The nematophagous fungus, Duddingtonia flagrans , isolated from a fresh sheep faecal sample obtained from a farm in northern New South Wales, Australia, was subjected to a number of in vivo investigations in both surgically modified and normal sheep to determine its capacity to survive passage through the gastrointestinal tract. Single and sustained dosing experiments established that between 5×10 5 and 10 6 chlamydospores/day resulted in a substantial (>80%) reduction in the number of infective larvae derived from nematode eggs in faeces. This effect can be maintained if dosing continues. These results demonstrate for the first time the potential of nematophagous fungi to be deployed by means of sustained release technology in the biological control of nematode parasites of livestock.