Assessing the nematocidal antagonism of two nematophagous fungi: Dactylellina candida and Arthrobotrys musiformis (Orbiliales) against Haemonchus contortus in the presence of crude extracts of different nematodes as potential elicitors.

This study assessed the predatory activity (PA) of Dactylellina candida (Dc) and Arthrobotrys musiformis (Am) against Haemonchus contortus infective larvae (HcIL). It also examined the effect of crude extracts from HcIL, Panagrellus redivivus (Pr), and Turbatryx aceti (Ta) on liquid cultures of these fungi as potential enhancers of their nematocidal activity against HcIL. The fungi were cultured in sweet potato dextrose broth (SPDB), and the corresponding nematode crude extract (NCE) was added to flasks containing the fungus. Control groups included fungi without extracts and media alone. Liquid culture filtrates were assessed at three concentrations (100, 50, and 25 mg/mL) against HcIL during 72 hours at 18-25°C. The highest mortality (86.61%) was observed with Dc stimulated by HcIL crude extract (HcCE) at 100 mg/mL (p < 0.05). Arthrobotrys musiformis showed 47.49% mortality when stimulated with HcCE. Both fungi increased their nematocidal activity when exposed to HcCE, demonstrating their potential nematocidal activity against H. contortus.