In-Vitro Sensitivity of Infective Larvae of Oesophagostomum Species to Nematophagous Fungi | VetScan 2012 Vol 7 No 1.docx

Two experimental assays (A and B) evaluated the action of conidia of the nematophagous fungi Duddingtonia flagrans (AC001), Monacrosporium sinense (SF53) and Artrhobotrys robusta (I-31) against infective larvae (L3) of Oesophagostomum spp in 2% water-agar (2%WA) medium and coprocultures. The first assay consisted of three groups of 1000 Oesophagostomum L3 treated with 1000 conidia of isolates AC001, SF53 and I-31 and control without fungus plated in 2% WA. In the second assay, 1000 conidia of the same isolates were added to 20g of feces and incubated at 26°C for 8 days. The L3 no predate were recovered after this period fungal treatment. There was no variation in the predatory capacity among the tested fungal isolates (p>0.01) during the experimental period of seven days. There were significant reductions (p<0.01) of 94.4%, 92.9% , and 88.3% in the means of Oesophagostomum L3 recovered from the treatments with isolates AC001, SF53 and I31, respectively, when compared to the control treatment. Second assay also showed statistical differences (p<0.01) between the means of recovered L3 in the treated groups and the control, with the following percent reductions: 75.3% (AC001), 63.7% (SF53) 63.3% (I-31). In this study, the three isolates of predatory fungi D. flagrans (AC001), M. sinense (SF53) and A. robusta (I-31) were efficient in the in vitro capture and destruction of Oesophagostomum L3 and are potential biological control agents of this nematode.