Abstract:

The aim of the present study was to investigate the effect of seven entomopathogenic fungi (Aspergillus californicus, Beauveria bassiana, Fusarium oxysporium, Metharizium flavoride, Cladosporium cladosporioides, Trichoderma viride and Verticillium alfalfae) against aphid insects: Metopolophium dirhodum. The selected entomopathogenic fungi were isolated from the agricultural soil of the National Institute of Plant Protection of Constantine, Algeria, and were tested against aphid insects that were gathered from the same area. The aphids were exposed to each fungal spore suspension (107 conidia/mL) for 10 seconds. The viability/mortality of the insects was evaluated on the 1st, 3rd, 5th, and 7th day after inoculation. After 7 days of inoculation, all the fungi species, except F. oxysporum, presented a significant effect (P < 0.05) against the studied aphid. The mortality rate was estimated between 21 and 96%. B. bassaian, C. cladosporioides and V. alfalfae presented the most potent effect on M. dirhudum with a percentage above 50% (95.83, 63.98 and 51.83%, respectively). A. californicus and M. flavoride showed the same effect: 41.97%. T. viride and F. oxysporium had the lowest effect with 31.44% and 20.83%, respectively. The inter/intra specificity of the fungi was mostly reported, besides other factors, as the modulator of their effectiveness. 

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