The use of image analysis to study the effects of residues of esfenvalerate on the locomotory behaviour of Panonychus ulmi and Typhlodromus pyri (Acari: Tetranychidae, Phytoseiidae)

The influences of esfenvalerate on mite behaviour were investigated by image analysis. Video recordings of the locomotory behaviour of two mite species were converted into a series of x,y coordinates that, when joined, closely resembled their paths. These coordinates were used to calculate walking speed, direction of travel, turning frequency, turn bias and tortuosity. Two experimental arenas were used: (1) a leaf disc arena for the European red mite, Panonychus ulmi and (2) a glass coverslip arena for Typhlodromus pyri. The behavioural responses of P. ulmi and T. pyri to esfenvalerate (field rate) indicated that these mites did not show a preference for the unsprayed halves of the arenas during the first 48 min. However, significant differences between most of the behavioural parameters to esfenvalerate residues were found with P. ulmi when whole arenas were compared. © Rapid Science Ltd. 1998