PROTOTYPE OF A VISION BASED SYSTEM FOR MEASUREMENTS OF WHITE FLY INFESTATION

To better respond to ecological and economical aspects of plant production than has been the case in the past, plant protection measures have to be better adapted to reflect actual pest densities in cultivated plant populations. Because the currently applied methods to determine entomological pest densities are time-consuming manual methods, there is a general need to automate this process. A system has been developed to measure the density of an entomological pest, the white fly (Trialeurodes vaporariorum and Bemesia tabaci), within plant stands (Lycopersicon lycopersicum). The system combines automatic pest insect extraction with a computer image analysis unit, and has now reached the prototype state. A mobile aspiration mechanism with a newly developed mechanical filter system is applied to collect adult white flies. The collection unit can extract pest individuals from the plant population and feed them to an optical recognition system. Particles which are loosely attached to the upper section of the plant stand are aspirated, filtered out of the air stream, put on a conveyor belt and transported in front of a color CCD camera. Digital image analysis is then performed to classify the captured objects into "target organisms" (white fly) and biotic or abiotic "error items" (foreign organisms, dust, plant parts). Shape and color parameters serve as differentiation criteria. Finally, these characteristics are compared to a classification dataset for the white fly and then evaluated.