Characterization and virulence of Lecanicillium lecanii against different aphid species

Abstract

Seven isolates of Lecanicillium lecanii (Zimmermann) Zare & Gams isolated in Spain from infected aphids were characterized using sequences of the Internal Transcribed Spacer (ITS) regions and also based on morphological and physiological characteristics. Four of these seven L. lecanii isolates were selected to assess their virulence against nymphs of Myzus persicae (Sulzer), Nasonovia ribisnigri (Mosley), Macrosiphum euphorbiae (Thomas) and Aphis gossypii Glover. Mortality (%), lethal concentration 50 (LC 50 ) and lethal time 50 (TC 50 ) were calculated. The analysis of the sequences of ITS region confirmed that the new isolates were clearly Lecanicillium lecanii. The set of isolates had similar radial growth (51.5-54.0 mm), except for ICAL1 (39 mm). The germination time 50 (GT 50 ) varied between 10.7 h (ICAL3) and 13 h (ICAL5). The isolate ICAL6 showed the highest value for conidial production (3.4 9 10 8 con ml -1 ) and also produced the highest mortality for M. persicae (95%) and was more virulent than the commercial product Vertalec Ò (91.6%).

Effects of the fungus Lecanicillium lecanii on survival and reproduction of the aphid Schizaphis graminum

“…The results demonstrate that this strain has antagonistic effects on aphids, confirming the data already obtained for other strains of the same species or genus (Å sman 2007; Diaz et al 2009;Kim et al 2007;Loureiro and Moino 2006;Roditakis et al 2008;Vu et al 2007). Moreover, this study showed that L. lecanii interacted differently with alate and apterous morphs, with lower Lethal Time (LT) values for alate morphs.…”

“…Comparison of the lethal effects of different isolates used by other authors (Alavo et al 2001;Askary et al 1998;Å sman 2007;Diaz et al 2009;Fournier and Brodeur 2000;Kim et al 2007;Loureiro and Moino 2006;Safavi et al 2002;Sugimoto et al 2003) is difficult since the mode of distribution of the fungus and experimental conditions vary greatly, and different aphid species and developmental stages were considered. In addition the recent split of the species V. lecanii into different species (Zare and Gams 2001) make the comparison even more difficult.…”

“…Numerous studies have evaluated the potential of microscopic fungi and their metabolites as biopesticides (Ashouri et al 2004;Baverstock et al 2006;Butt and Goettel 2000;Butt et al 2001;Diaz et al 2009;Fargues et al 2003;Kaufman et al 2005;Kope et al 2008;van Lenteren 2000). Recently entomopathogenic fungi belonging to the species Verticillium lecanii have been attributed to a new genus, Lecanicillium, and in addition split into different species (Zare and Gams 2001).…”

“…Recently entomopathogenic fungi belonging to the species Verticillium lecanii have been attributed to a new genus, Lecanicillium, and in addition split into different species (Zare and Gams 2001). Fungi belonging to this genus are known to be pathogens of aphids (Alavo et al 2001;Askary et al 1998Askary et al , 1999Å sman 2007;Diaz et al 2009;Feng et al 1990;Fournier and Brodeur 2000;Kim et al 2007;Loureiro and Moino 2006;Safavi et al 2002;Shah and Pell, 2003;Steenberg and Humber 1999;Sugimoto et al 2003;Vu et al 2007) and consequently have been considered as candidates for biological control. In addition, fungi of the Lecanicillium genus have been discovered as being active against fungal plant pathogens suggesting that such entomopathogens could be developed as a dual-role mycopesticide .…”

Greenhouse crops protection against suctorial phytophages complex with the preparation based on the entomopathogenic fungus “Lecanicillium lecanii” (Zimm.) Zare & W. Gams

“…Zare & W. Gams makes a practical interest as a pathogen of arthopods. Literary sources identify an ability of L. lecanii to regulate the number of pest populations in protected ground (Chandler et al, 2005;Diaz et al, 2009;Patogeny..., 2001;Gurulingappa et al, 2011;Scorsetti et al, 2008;Vestergaard et al, 1995). The main advantage of this pathogen lies in the ability of a percutaneous penetration in a host organism, and, hence, a suitability for an application for the control of suctorial pests (aphids, thrips, whitefly and spider mite), which aren't susceptible to contact and intestinal insecticides action.…”