Mechanical distribution of entomophages on a protected crop

Increasing demand for farm produce obtained using methods of biological pest control, together with the onset of resistance phenomena in some pathogens to the more common pesticides, have led to the development of control techniques based on the use of beneficial organisms. Distribution of these natural enemies, currently prevalently manual, could be improved in terms of technical and economic efficiency by introducing mechanical distribution systems. This paper describes the development and use of a prototype for the mechanical distribution of entomophages. The functioning of the equipment was verified in laboratory bench trials for the characterisation of the distribution diagrams, varying the main regulations of the working parameters of the machine (delivery of material and air speed). Releases were conducted of the phytoseiid Phytoseiulus persimilis Athias-Henriot to control the mite Tetranychus urticae Koch on aubergine in the greenhouse. Both the distribution diagrams and biological responses in the greenhouse (phytoseiid viability, control of the pathogen, crop yield) have demonstrated that the efficacy of the machine is the same as that of the control manual distribution, but with working times reduced by 90%.