Biocontrol solutions against Myzus persicae

The �Evaluation of biocontrol products� project of the French National Research and Innovation Plan (PNRI) aims to identify and evaluate biocontrol products to contribute to the reduction of chemical pesticide uses in cropping systems. In this project, a broad screening of biocontrol products, mainly with aphicidal action, was conducted to identify promising active substances for controlling Myzus persicae, the main vector of sugar beet yellows viruses. The efficacy of biocontrol active substances was first tested in greenhouse conditions (28 active substances from 33 different suppliers), and the 10 most efficient solutions were then evaluated in field trials, alone or in combination with the reference chemical product (flonicamid). Greenhouse experiments showed that biocontrol products were highly effective in controlling the development and dispersal of aphid populations, compared to the chemical reference. However, the efficacies observed under controlled conditions were not observed in field trials. The majority of biocontrol active substances shows a significant drop in efficacy, except maltodextrin and two combinations between the conventional aphicide and biocontrol active substances: entomopathogenic fungus Lecanicilium muscarium + flonicamid and kerosene oil + flonicamid. However, the current efficacy of these products, according to their costs, often remains insufficient for them to be adopted by sugar beet growers.