Aphicidal potential and virulence of Lecanicillium fungi from Argentina.

MANFRINO ROMINA; SAAR KATHARINA; GARCÍA JUAN JOSÉ; LÓPEZ LASTRA CLAUDIA C. ; LECLERQUE ANDREAS; SCHUSTER CHRISTINA; TORNESELLO GALVÁN JULIETA

Tours

Congreso; International Congress on Invertebrate Pathology and Microbial Control, 49 th Annual Meeting of the Society for Invertebrate Pathology.; 2016

Society for Invertebrate Pathology

Mitosporic fungi of the genus Lecanicillium (Ascomycota; Hypocreales) are of particular interest as biological control agents for phloem-sucking plant pests including aphids. Bioprospection for these fungi in Argentina has given rise to a set of single-spore derived Lecanicillium strains isolated from a wide range of original hosts.For species-level characterization of Lecanicillium isolates, five genetic markers comprising one mitochondrial (NMS) and two nuclear (ITS, IGS) ribosomal RNA operon together with one mitochondrial (nad1) and one nuclear (ef1) protein-encoding sequences, has been employed. The aggregated information from these markers indicates that fungal isolates from Argentina mainly, but not exclusively belong to the Lecanicillium core species.Moreover, Lecanicillium strains has been investigated for fungicide sensitivity. Between strains differences in susceptibilities have been found to be important and not necessarily in line with systematics, making careful determination of sensitivity to agriculturally used fungicides an important criterion of biocontrol agent selection. However, the fungicidal polyketide compound soraphen has been found of outstanding activity against a wide variety of isolates from all species investigated.On the basis of these results, some strains have been selected for virulence bioassays against Brevicoryne brassicae. For each replicate 15 apterous adults were used. The applied dose was 1.107 conidia/ml and the application method was spray. After treated, aphids were placed on each seedling and mortality was controlled during the 10 days after application. The strains that caused the highest and the lower mortality were 155 (66.6%) and 182 (31%), respectively.