In vitro ovicidal activity of the nematophagous fungi Duddingtonia flagrans, Monacrosporium thaumasium and Pochonia chlamydosporia on Trichuris vulpis eggs.

Abstract

The in vitro effect of four isolates of the nematophagous fungi Duddingtonia flagrans (AC001), Monacrosporium thaumasium (NF34a) and Pochonia chlamydosporia (VC1 and VC4) on the eggs of Trichuris vulpis was evaluated. One thousand eggs of T. vulpis were plated on Petri dishes with 2% water-agar with the fungal isolates grown and without fungus as control. After 7, 14 and 21 days 100 eggs were removed from each plate and classified according to the following parameters: type 1, lytic effect without morphological damage to eggshell; type 2, lytic effect with morphological alteration of embryo and eggshell; and type 3, lytic effect with morphological alteration of embryo and eggshell, besides hyphal penetration and internal egg colonization. P. chlamydosporia demonstrated ovicidal activity (p<0.05) on the eggs of T. vulpis in the studied intervals presenting type 3 effect of 29.5% (VC1) and 36.5% (VC4), 59.5% (VC1) and 2.5% (VC4), 94.8% (VC1) and 2.95% (VC4) at 7, 14 and 21 days, respectively. The other fungi showed no type 3 effect. P. chlamydosporia should be a potential biological control agent of T. vulpis eggs.